recover deleted files

Hi,

does anyone know of a way to revert to the original state a whole filesystem
where rm -rf has been issued? No subsequent changes have been made, the system
is still running in single user mode and has been left alone just in the state
after the deletion. 

Any help very much appreciated - this was my *backup* volume, and a misleading
backup tool (rdiff-backup) did this horror to me in a regretful situation during
restoring the system itself from the backup.

bye
mortee