There is currently an undocumented enrollment bonus for Canadians. Recieve 3,500 bonus miles upon enrolling in the Mileage Plus program.
New members recieve:
Web Enrollment Bonus - 500
Canadian Web Enrollment Bonus - 2,500
Web Newsletter Opt In Bonus - 500
For a total of 3,500 miles.
This bonus works for Canada-wide postal codes. It does not work for new USA accounts (although, you can get the miles if you have a nice Canadian friend who is willing to let you virtually move-in for two weeks).
Enjoy!