The working visa has some restrictions - you must be between 18 and 30. It's only valid for 12 months and you can only work for a maximum of 6 months for any one employer. The last provision is a bit tough, but there are still plenty of 6 month contracts around.
Why do Americans have such a strong reluctance to travel abroad for work? I've never understood it. It's a great opportunity to get some work experience, live a little and, particularly for the mid-west and east coasters, skip winter!