Also, could someone clue me in on this "hack" I've seen mentioned on several posts? How in the world does it work? It's something that effects the camera itself? How?? Type slow, I'm pretty new to digital. <G>
A group of programmers figured out that the 10D and 300D share the same firmware. They then modified the bios for the 300D so that it is accepted by the Rebel but enables the extra 10D features. You are not getting a 10D but you are getting some more features including FEC (Flash exposure compensation) for both the internal flash and the external flashes (like the 420) that don't have a manual override for FEC.
The obvious caveats will apply if you install it. You may void your warrenty. You may damage the camera. If Canon ever comes out with a newer firmware it may be more aggressive in it's turning off features so you may lose those features in the future.
For somebody that is not digital savy youwill probablybe better off with the Sigma as suggested by NHL.