The simple answer is just start calling and find out what agency has jobs, and which ones you feel comfortable in working for. You can't avoid legwork, but I might be able to help you shortcut a bit. Psych is not a large specialty, so agencies with lots of choices are limited. Any agency can pick up a psych assignment, but some will have more than others. Supplemental Healthcare started by specializing in psych and I hear they still have a lot. A spinoff from them, Worldwide, may also do you well. Otherwise, really large agencies such as American Mobile and Cross Country are your best bets.