Via's Pico-ITX motherboard was small and powerful to begin with, but their new Mobile-ITX platform is about half the size and supposedly still packs a punch while keeping power consumption low.
Because of that low power consumption and tiny package, the Mobile-ITX should be great for always-on devices and even smaller gadgets. As far as whta features it brings to the table, it looks like there's support for "core CPU, chipset and memory functionality and I/O that includes the CRT, DVP and TTL display support, HD Audio, IDE, USB 2.0, as well as PCI Express, SMBus, GPIO, LPC, SDIO and PS2 signals." Wowza. Quite a lot for such a small fellow. [Hot hardware via Engadget]