DIY multitouch isn't new - we've featured quite a few home-grown rivals to Microsoft's Surface here on SlashGear - but MaximumPC's tutorial does stand out by virtue of its completeness. Thanks to having a spare PC and projector to hand, they spent just $350 on making their multitouch table.
Video demo after the cut
They've also used some silicone sealant so as to make a more consistent touch-surface, which is perhaps the first time we've seen that being done on a DIY project.
Of course, how much you'll pay to run through a project like this yourself depends on how much of the equipment you already have lying around. The most expensive component is invariably the projector; if you've got that, and a suitable PC to do the number crunching, then you can have your own multitouch setup for a few hundred dollars.