NSLU2 on wikipedia.
From the NSLU2 home page:
This is the web presence of the NSLU2-Linux development group and user community. We discuss, develop and modify the firmware and hardware of the Linksys NSLU2, the Synology DS101, the Iomega NAS100d, the D-Link DSMG600, and other ixp4xx-based devices with large attached storage. Purchase a Linksys NSLU2 and join our community if you are interested in doing the same.