Slightly less technical review here...
I treated myself to a Pentax K100D as a post-Christmas present, and I've been extremely pleased with it, especially for a relatively inexpensive intro DSLR. My only SLR before this was a Pentax K1000, which I absolutely loved, so I wanted the next-best thing in a digital format.
I originally was looking at the K110D (same camera, minus image stabilization), hoping to save a few bucks. Luckily, my boyfriend convinced me that I would be much happier with the IS, and I'm glad I listened. When we went to NYC, I didn't want to be bothered carrying a tripod around, and the image stabilization made one of my favorite pictures possible.
ISO400, 1/10th sec, f/3.5, completely handheld. I could never go back to a camera without image stabilization now.
I really like the feel of the camera. Solid, well-built, not quite as "built like a tank" as my K1000 (I wouldn't take it out in a rainstorm like I did with the K1000), but with a digital, I want to be a little careful anyway.
Being the owner of the K1000 50mm f/2 kit lens and a Pentax 28-80mm zoom, the ability to use the lenses I already owned was a huge plus for me. The 50mm lens doesn't have auto aperture, but the camera has a setting to allow for usage of an aperture ring, and I discovered that lens actually makes a great portrait lens for the K100D.
One slight pitfall to the claim that the K100D can use any K-mount lens: this is only 100% true if it is a Pentax brand K-mount lens. I purchased a Sears brand 70-210mm f/4 lens for cheap off eBay, and made the unfortunate discovery that non-Pentax K-mount lenses have an extra pin in the mount, which gets stuck in the autofocus screw on the camera. Luckily,
this tutorial posted on dpreview shows how to get the lens off the camera if it gets stuck, and describes how to remove that pesky pin so you can actually use off-brand lenses on the newer cameras.
The previous reviewer mentioned the auto white balance issues in artificial light, which do tend to be a bit of a problem. However, it's fairly easy to set a custom white balance, which I do almost without thinking about it whenever I'm taking pictures around my apartment, in mixed lighting. If you shoot RAW, it's also dead easy to change the white balance in the RAW processing software.
The current list price for the body and the 18-55mm kit lens, according to the Pentax website, is "under $700". I managed to snag mine while holiday rebates were still in effect, so after rebate, I paid $506. So, amazing value for the features!
For an semi-serious amateur (like myself), I found the K100D to be perfect for everything I use it for thus far, like the K1000 before it. Another great learning tool that takes high-quality photos from Pentax!
Score: 9/10