VIA announced that it will be selling a new product line soon: the Pico-ITX board. It measures 3.9 x 2.8 inches, is MUCH smaller than the already small Nano-ITX boards (which is much smaller than the current mini-itx boards to begin with), and will have an integrated 1 Ghz cpu. This would make a great back-end for a touchscreen setup.
Source: LinuxDevices.com
Source: LinuxDevices.com