Haven't seen much use for MSN TV (previously known as Web TV), Microsoft's info appliance for TV-based web surfing. But some dude has not only been able to get the box to run Linux, but is actually building a server cluster out of them. The hack does involve some hardware mods, so it's not necessarily something for casual scripters to undertake (and it's certainly not something any of MSN TV's target users will ever attempt), but considering you can pick these up on eBay for a buck, it could be a pretty cheap way to build your own server farm if you've got the chops to make it work.