Repairlix is a networked Linux distribution/bootable system intended to fit in 12MB of media - so small that an image can be burned onto a business-card-sized shaped CDROM, suitable for your wallet. It has a suite of utilities for doing system recovery.
Repairlix is now in the early stages of being useful. These early releases contain only enough logic to produce a bootable x86 ISO image, with perhaps some useful applications.
No testing has been made to verify that any of this works on other architectures, although it should be highly portable to any system that supports the El Torito bootable spec.
(Note: This only applies to the sources. I only have access to x86 architectures, so that will be the only platform for which I can build the ISO images I distribute. Therefore, these will be useless on other architectures.)