Ever lost a day's worth of editing on Unix by
fat-fingering something like “rm * .o”?
Flashback makes a gzipped tar snapshot
of the directory you're working in (and any subdirectories)
to a common backup directory from which you can restore
clobbered files when needed. Flashback reports the
size of the backup directory after adding the new backup so
you'll know when it's time to clean up old backups.