Pentax K100D does a wonderful job of balancing the needs of amateur and experienced photographers. It doesn’t have some of the more fancy features, such as white-balance bracketing or dynamic range optimization, that you’ll find on more expensive cameras, such as the Canon Rebel XT or the Sony Alpha DSLR-A100K, but for its price, the K-100D is a steal.
If you already own Pentax lenses, this camera is a no-brainer. On the other hand, if you’re really looking to save money, and shake reduction doesn’t float your boat (though it probably should), then you can always step down to Pentax K110D, which is the same camera without the shake-reduction feature.