Unfoo is a little shell script I hacked out quite a long time ago because I hated remembering tar's commandline options. It also handles multiple files cleanly, and as of 1.0.5 even files with spaces in the names.
The really sad thing is, even after ~3 years of this existing solely as a dirty hack, I still miss it when I don't have it.
For the opposite of unfoo, please see foo.