A710IS! I think it should be around this price range. I'm a very happy user of this camera - manual modes, great colors, IS (which has become really important cos' I am limited to available light most of the time and usually shoot at 1/5 sec - 1/60 sec handheld) and so much more!
The S3IS is a great idea too but the 2.0in LCD may be a bad thing. Other than that, the features (esp the 100% EVF) is really a notch above the A710IS.
Another camera worth consideration is the Sony W80/90. You can get a W80 for $405 with 1G Memory Stick Pro Duo, without camera bag for this price.
1. Optical Image stabilizer
2. Reasonable low noice at high ISO.
3. 2.5" LCD, with optical view finder, this is useful, when you are running low on battery, turn off the LCD while shooting can squeeze out more shots.
4. Smaller size than the Fuji F31fd, but then shorter battery life.
I have both Fuji 31fd and Sony W80, did a test shot at low light condition, find the performance to be about the same, Sony has more noise at same ISO than, but with IS, it is able to compensate the noise by lower ISO, slower speed and yet achieve the same result.