Our visas are set to expire in October and we have to get a new stamp to avoid any issues with the immigration auhtorities when we come back from India after the vacation.
The issue is I used to work with a company A and then I got the H1 visa transfered to another company. So I had to get the visa on the new company's name. This seemed a little risky but I had all my supporting documents ready.
Documents : I have all the documents and pay stubs. Here is what you need.
1. I - 797 (Original as well as the transfer)
2. Passport (ofcourse)
3. Most recent pay stubs. Most companies offer online pay stubs and its ok to print them if you have not get the ones in mail.
4. All the W2 documents and if possible the Tax return documents.
5. Bank statement.
6. All your certificates.
7. You might also need the education evaluation documents. They would be a part of your H1 filing documents that your employer gave you.
8. Employer and Client letters about your pay and job.
Well all the above are important. And its better to take all the documents rather than feel sorry later.
Getting Canada Visa:Getting Canada visa is the step 1 of the process. A US visa interview in Toronto needs a visa to Canada (unless you are a Canadian). If every thing goes normal, you can get the Canadian visa in mail in about a weeks time.
http://geo.international.gc.ca/can-am/main/visas/fee_schedule_us_dollars-en.asp is where I would start.
Our case, we wanted to go there in person. When we mailed the documents last year to visit Niagara Falls, they sent the passports back for want of a document. We ended up visiting Niagara from the American side and the Canadian side was left pending.

So, If you decide to travel to Detroit or another Canadian embassy, here is what you can do :
1. Download all the application forms from the above mentioned URL.
2. Your i -797
3. Bank statement
4. Letter from the Employer
(This is a compulsion)5. Recent Paystubs
6. All your documents and Passport (ofcourse)
The process in Detroit takes about 2 hours on a normal working day. The Canadian consulate is in the Renaissance Center in Downtown, Detroit.
We stayed in a Motel, 1 hour away from Downtown and we drove to the consulate early in the morning. There are a lot of public parking spaces available and for about 8$ you can park your car. There is a train loop that takes you around in downtown and the fare is a mere 50 cents.
This train takes you directly into to the renaissance center. Finding the Canadian consulate is not tough and any security guard would be able to put you in the correct direction.
Try to be there at the consulate by the time they start accepting the applications and you would save the entire day.
If you miss the documents and wanted to get some printed or downloaded, dont look for a kinkos, instead, ask for the business center for the hotel in the building. That is fast.
Any way, the Canada visa for us took about 2 hours and we were out with the visa. Make sure to check the names on the visas since I had my name incorrectly printed there.
You can pay the fees in USD at the Canadian consulate. Thats very cool.
Getting An appointment in the Toronto Consulate : This is the tricky part.
https://www.nvars.com/ is the website to make appointments for the Visa. You need a credit card and your passport number to make appointments. Generally, there are no appointments available for the next day. You need to keep an eye on the calandar and book one when there are appointments. If you are in a hurry , try Halifax and Calgary . They have more appointments than Toronto. For us, we had time, so we picked Toronto.
The key is they add new appointments regularly between
7am-9am EST(The site says 7am-10pm but I obeserved that this time window is more frequent). If you check during that time, the chances of you getting an appointment are good. The web site charges 9$ - non refundable for the appointment. The good part is you can always reschedule the appointment once you book it and there is no additional fee for that.
Make sure you have all the documents filled. DS 156,157 (for you and your spouse) and 158 for you. Make sure you put all the info and None, NA where ever they are applicable. If you dont, then the person checking your documents before you enter the actual counter, would mark them with a red coloured pen that shows up odd and might get unwanted attention from the person interviewing you.
Get all your documents ready and in parallel plan your trip.
Planning your Trip :The US consulate in Toronto is in Downtown Toronto. If you fly in to Toronto then try to look for a hotel close by to the consulate. There are a lot of hotels. If you want a 4 star hotel then use
http://www.priceline.com/ . There you can expect a room for 95$ per night and that would be cool because you would be saving on Taxi when compared to a cheaper hotel slightly away from the downtown.
Reaching the Hotel from the Airport : There are airport shuttles which have their numbers online and you can book one of those. If you plan to rent a car then make sure you have GPS with you. Most GPS devices work in Canada. Donot rent a car from places like Pay less. They seem cheap but the over heads would make them no cheap. I suggest companies like Avis/Budget/national which are slightly cheap and have a kiosk in the Airport. This saves a lot of time. Trust me. Also, Rent a car only if needed. Parking in Downtown is a pain.
The subway system in Toronto is very simple with just two routes. Once you know your hotel, some homework with the subway system online would save you unnecessary headaches.
From the airport, take the bus to Kipling subway station (costs you 2.75$). The subways take you into downtown and most downtown hotels are walkable from the closest subway station. I would suggest this mode of transport if you are travelling from the airport.
Tip: If you are flying in into Toronto, try to be prepared to stay there for 2-3 days since the Visa now takes 3 days (this is the current info from 1st Aug 2007). We had a bitter experience with the airlines as they quoted 500$ each for rescheduling our journey. So, even if its slightly expensive, try to get a flexible ticket (If there is one of that kind)
Attending the Visa: Try to reach the consulate 15-20 mins earlier than your appointment time. They would let you in. Once In, they would take your 156,157 and 158 (for H1-B and other technical visas) along with the passport and your approval document(797 - in most cases).
Be prepared to spend 2 hours there atleast. The officer there generally has few items to worry about. Your confidence is the first thing. Remember that you are not illegal in the US so be confident. I saw a couple of guys who were tense and were asked more questions than the confident looking fellows.
The Application Fees is to be paid in any Scotia bank. The problem is if your appointment is at 8am or 830 am, there are not many banks open at that time which are close to the consulate. You have to find some one who can pay the fee on your behalf and pick uip the receipts from them. They dont accept Credit cards and Cash.
They take the documents, call you to verify the finger prints and then finally for an interview.
This is when, they might ask you for the extra documents.
All this time, you would be made to sit in a small room with all the other applicants.There would be water, no food allowed. So try to eat some thing before you go.
They would give you a slip that says when to come and collect the Passport. After that you are free to go.
Toronto :

The Niagara falls from the Canadian side is much better than the American side.The drive is about 1.5-2 hours. We stayed a day there. By the way, try going to Niagara falls early in the morning. There would be absolutely nobody and its a good experience.
Down town Toronto is very good. There is a Mall in the center called the Eaton Center. That is very close to the Consulate and 2 blocks away. This is a good place to spend some time.
Tim Hortons is a breakfast/bagel place that can be found at most locations in Canada and it appears as if its Canada's most preferred food place.

We chose to travel back to the USA in a Bus (Grey hound from Toronto - Detroit.). The Grey hound bus stop is right in the downtown and 2 blocks away from the Consulate. If you have to check out from the hotel by Noon and pick your passport by 3 pm, You can keep your luggage in the Lockers provided at the Greyhound bus stop. They cost about 2$ CAD for 24 hours.
Money and Exchange:
Use Credit cards where ever possible. Withdrawing CAD from the ATM machines would add an unnecessary surcharge and exchange rate (Do it only if necessary). Instead use USD for purchases ranging till 5$.Most people accept USD so no issues there. The USD and CAD are almost same and it appears that they would be equal in the days to come.