I got my H1B extension last October and I'm going to Canada soon so I can get a stamp in my passport on the way back.
When I got my original H1B, I just went to the airport with the i797 form, filled out the I94 and that was it. My friends that are non-Canadians all had to go to US embassies in their countries.
Since US made the change requiring Canadians to have passports when entering the US, I was just wondering if they also changed the way Canadians can just show up at the border/airport with I797 form and get the H1B stamp?
Right, you only need to go to the border/airport. Canadians are still exempt visas for most nonimmigrant categories. By the way, you do not need to get any stamp on your passport. The extension is sufficient if the I-797 has the new I-94 attached at the bottom.