The viewfinder-equipped Panasonic DMC-G2 is pretty much on clearance right now, selling for $300 at
B&H and Amazon, since the G3 came out (which removes many of the on-body controls in favor of a lower price and a higher-megapixel sensor). I originally decided to buy the G2 to get good-quality pictures when I don't feel like having my D90 with me, but it's shown to have other uses as well.
I posted a while ago about making the jump to micro-4/3 cameras, but never did, until now. This is an especially useful deal for photographers that have a large 35mm collection of "dead" mount lenses: Contax, Leica, Konica, Canon FD, Nikon non-Ai, etc. Dead in the sense that there's no digital camera out there with a mount for the lens. Extra bonus points for those lenses that don't have AF or any electronics to worry about or weigh down the lens. Since the flange distance on these cameras is so short, you can buy an adapter for most any mount. I have some Hexanon and Rokkor lenses in the closet that I feel are about to get new life.
Until Nikon comes out with a D3000-sized camera that not only mounts non-Ai lenses, but meters with them as well, I'm going to try this out. The GF2 appears to be the best micro-4/3 "SLR" type camera, besides Panasonic's new flagship GH1, which sells for about $1,000. This camera has a viewfinder and on-body controls that make "serious" shooting easier. But look at how small it actually is in-hand:
Voigtlander f/0.95 25mm Micro 4/3 Nocton Panasonic Lumix DMC-G2 Digital Camera Body DMC-G2KBODY B&H Photo