You could go to the website of your state's contractor board and go through all of the new contractors and contact the ones in your area. I do this when I'm trying to open commercial accounts for the company I work with.
The problem with this is you will get a lot of subcontractors more than the generals.
The best way would be to go to your court house and ask for a list of all building permits sold for new construction. Make your rounds and talk to the contractors. Most will already be using somebody else but if their normal guy is booked when they need him (doubtful in this market) you should now hopefully be next on his list.
I wouldn't bother sending mail unless possibly a post card. I used to be a general contractor and got so much mail that only the stuff I recogonized or was looking for got opened.