Leading Forbes' list of uber-cheap PCs (all under $300) is the $85 MicroClient JrSX from Norhtec, a book-size desktop that boasts (or perhaps doesn't) 128MB of RAM, a 300Mhz processor and a flash card-based storage system. Missing from the package are a keyboard, mouse, monitor and audio. That's right, no audio. Anything with sound would probably make it crash, anyway.
Also making apperances on the list are the OLPC and the surprisingly beefy-for-$220 Microtel MCS7001. While all are astoundingly cheap, let's just say their unspectacular specs preclude them from popping up on my Christmas list.