I'm brand new to the world of digital cameras, but bought two for Christmas- a point-and-shoot Canon (for my daughter), and a Canon XTi DSLR (for me).
Regarding the XT vs. XTi question above, I thought the larger screen, plus the extra pixels, if that's really of much value, made it worth the extra cost.
The flexibility and long-zoom possibilities that you have with the DSLR are great. For example, I've taken 600 or so low-light indoor shots at my sons' basketball games (1600 ISO; no flash; mid-to-high zoom) that just wouldn't have been possible (I don't think???) with the point-and-shoots.