I ordered three TP-Link WR703n's planning to use them as access points only to discover what great hacking platforms they are. The WR703n is a small chinese wireless router that's supposed to use 3G usb dongles but with OpenWRT it becomes an embedded linux platform in a tiny package with wired and wireless connectivity and a USB port for peripherals. With a little more hacking it's possible to add a serial port, some gpio pins, and bigger antennas. I haven't had them for very long so I can't speak to their reliability, but so far they work great and I plan on ordering more for future projects.
If anybody is interested in some of these let me know, I'd like to get a big order together and possibly buy some for the parts store. If you want one please vote "I'd like one now" or "I might use one from the parts store"
This Instructables has a lot of different hacks for it jammed together in one collage:

