H1B stamp expired, valid I-797 - Canada for re-stamping

[ra_visa]

Hi,

I have a valid I 797 until Nov'14 but my H1b stamp from previous employer expired in Sep'13.
I also have my perm filed from current employer which is in pending status right now

I understand to travel outside US I have to get my visa re-stamped but I am not planning to go to India soon although I will have to travel to other country for work for which I need the valid stamp to reenter US

So my questions are

1. Can I go to Canada to get my visa re-stamped?
2. What documents I need and which forms do i need to fill up?
3. Is it recommended to go to Canada to get the stamping done with valid H1B?
4. What is the process if anyone has done this earlier?

I believe this must be a very common situation and sorry if I am asking it again but I cannot find the complete information I am looking for

Thanks,
RA