Yes. We're inPulse (YCW11) and we hire Canadians. Hell, we're 3/4 Canadian at the moment. We're in Mountain View, CA.
We're looking for embedded software devs, Android devs and web/ops people. If you want an internship in the bay area, we pay market rate plus hook you up with living expense subsidies, free flights, food, etc. Send me an email: eric AT getinpulse.com
As a Canadian (Tdot).. I know it can be relatively difficult to get a job down here in SF. I was lucky enough to go to a US school which gets me OPT for a year. Then I can issue myself a TN-1 or H1B.
I'm a Canadian who has worked in the US a number of times as an intern. J-1 visas were easy to get for me through my University career office and employer working together.
I know plenty of bay-area startups hire undergraduate interns from the University of Waterloo (where I am).
I don't see it being a problem, though it's a little costly. You should contact a company like Cultural Vistas (http://www.culturalvistas.org/) who can get you the J-1 visa.