Those Linuxers just can't stand watching Windows 7 do something they can't, so the ENAC Interactive Computing Lab worked to get multitouch running in Fedora. And now you can, too.
Apparently, their solution requires Linux kernel 2.6.31, X.org 1.7 (modified), and a series of corresponding hardware and experimental drivers (including a simple Asus Eee T91MT).
So it's not quite turnkey, but if you willing to tinker a bit, all the resources are online to run a multitouch version of Linux on a few different hardware platforms. And if you're running Linux, there's a good chance you're willing to tinker a bit. [ENAC Interactive via Netbook 3G via lilliputing]