I'm always on the look out for small silent power-sipping computers. My home server is an NSLU2, and I love it in many ways, but its performance and memory size remind me of the PC I had 15 years ago.
The other day I discovered the Beagle Board. It has a 500MHz superscalar ARM processor, 128MB of RAM, an SD card slot, a USB port, and video output, all for 150 USD. Lots of information is available at beagleboard.org and the embedded Linux wiki. And there are a bunch of demo videos on youtube.
This might well be the successor to my NSLU2 (though I'll wait for the Rev C board, which should have the main USB port working — the earlier revs have to do everything through the little USB OTG port). It's a shame there is no case for it, but I'm sure I'll be able to work something out.