My Network Lunchbox project (originally I was going to name it palantir) aims to provide a ready-to-use image for Soekris net4801 (and possibly 4501) to make them usable as general-purpose network troubleshooting devices. Specifically, the intent is enable administrators of large, complex or geographically dispersed networks to be able to install a Soekris device with one interface on a network reachable from their workstation and use the other two interfaces as entry points into unreachable or problematic networks.
Full information, along with full image file downloads, can be found at http://lunchbox.jasonantman.com/.