With film, lenses were the most important thing you could buy, the camera was just a box that held the film. Digital, the camera in effect is also the film, so that's important too, but you can get a nice spiffy camera and throw crap lenses on it and the pictures won't be so great.

As for Rebel XT vs. D50, the XT has a better sensor and image processor, the D50 feels more like a camera and less like a toy compared to the XT and has a couple other picture-taking features that the XT doesn't have.

If you're just going with cheapie deapie kit lenses, pick the camera that feels better in your hands and has menus that you can understand better.