I have never used a Sony camera, although, to be honest, I think that their entire line as well as the brand in general are overrated.
I have always been a fan of Canon cameras (my only digi cam so far has been an S400...great camera, but twice your budget). Canon does make some very good "budget digi cams, such as the A40, A60, A70, and A80.
But hey, just get whatever you like. At that price range, you obviously wont find anything that is really advanced, but basically anything will take fine photos.
I would say check out cnet.com They have a good assortment of in-depth reviews on digi cams....this will be useful, as many of these small cameras seem to be plagued with barreling and other distortion issues. Also, not all photo sensors are created equal.....
I know I'm babbling here, but basically, I'm saying to jsut go to the store and see what feels good to use, and then go on the net and read some reviews and opinions, or vica versa...