They call it mudding out there, I've worked out there as a sparky and they seem to drywall and tape and joint everything. Getting a work visa is like rocking horse sh!t. If you do go out there don't take your tools with you as they will send you back on the next plane. Buy your tools when your there that's if you can find any work there.
The United States are facing a double dip as are Canada, but the Canadian immigration are still saying they are short of certain trades folks? Probably just dangling carrots so their government department doesn't start laying off.
One thing I did notice though when I was there later on last year, is that plasterers tools are more resonably priced even in Home Depot. Which looks identicle to B&Q except the only difference is the sign. The price figures are almost the same as over here except the pound sign is taken away and a dollar sign is there. In Canada they have a dollar sign but the figures are higher than what they are over here.
Anyway mate I hope that you get out there and experience the good old US, its a great place to visit and to work rest and play. The people are great to get on with and the hospitallity is good as well.