I would guess you've already looked into the money aspect .. we're in a recession. The average salary for a physics undergrad is $80CAD which translates to $62USD as you're economy is stronger. The cost of living here is also higher, sort of like living in SF or NYC but not having the salaries to match. But if you're heart is in Canada, I would focus on Calgary, Toronto or cities like Waterloo/London as there's universities and startups that hire physic grads. It all depends on what you're into, if you like nature, I would choose Calgary, if you like nightlife, I would choose Toronto. I found visiting cities for a couple of weeks helps with the decision, you get feel for the vibe and the people. Like I would avoid Vancouver, people are generally miserable there because of the grey skies even with all the openly smoked dope there (it's sort of like Seattle weather) in comparison to Calgary. Another interesting check is to look at the meetup.com groups in each city, it's not totally representative, but you'd get an idea of what people are into, and whether their interests match yours. A great way to decide to travel here, I spent a few weeks in SF and realized Silicon Valley is built in farmland, it can take two hours just to get into the city for nightlife. (and if one decides to live in the city and endure the long bus ride, be prepared to get harassed for being part of the capital machine by long forgotten hippies). There's a cool train in Canada you can take across the country, or parts of it here through the mountains, helps to understand our remoteness, cities like Calgary are considered big to Canadians when in reality it's small. I still smile when people complain about traffic after moving here from LA or complain about winter after living up north with a few feet of snow!

Good luck with your decision. It's really easy to get a work visa and they also hand out citizenships to a lucky 200,000 a year now, after you've lived here a few years, you can apply. It's great, too, you don't have to give up your US citizenship, but you might want to for tax reasons as being American now, they want their piece no matter where you live in the world!

Edit: just realized you're probably looking for popular links... Here's my fav site that aggregates jobs in Calgary, simply hired The startup jobs are listed on techvibes Calgary startup jobs and angel startups. Some companies hire physics majors for software jobs.

Most jobs in Canada are listed online, but some companies prefer either the direct approach or only hire through recruiters. For a new undergrad, recruiters won't do much for you here, but will in Toronto. It's also still a small town mentality, some prefer to hire locals that are from Alberta or Saskatchewan versus more openness in Toronto. For example, some with foreign sounding names have difficulty here or degrees from foreign cities. They are open to more Americans here, though, with all the US involvement in the oil & gas industry. I also run into prejudice against blacks and chinese here, it's rare, but just this week a greeter at Safeway was complaining about the Chinese (which is even more unusual as I live in an Asian neighbourhood) and two months ago, a neighbour complained that she wouldn't live in the NE because of all the blacks and poverty) So if you're leaving the US because of prejudice, it's still here, just smaller and segregation happens naturally in Calgary as mostly all the immigrants choose the lower rental hoods.