Check out Strobist to see Paul Duncan's cheap and easy solution to ringflash. It's so simple you'll kick yourself because you didn't think of it first, and smart enough that you'll want to try it out. Paul built an elliptical reflector from cardboard and the dull side of aluminum foil to achieve the same effect as an expensive ringflash. The reflector goes in front of the camera, with the strobe positioned to one side, so the light bounces off the reflector at an angle. If you don't want to go the DIY route, check out the Alienbees ABR800 ringflash ($399, street).