One month ago I've deleted some files in a terrible mistake :)

On my personal server (dedibox) I'm using partimage to backup the / only, it's a nice tool that provide a way to restore a bootable partition from a backup, very usefull for a remote administrated server.

But my need was only to restore some missed files (without restore all the /), at this time I don't think partimage is capable of that, one solution was to create a virtual partition and let partimage restore in it:

# first create a file large enough to contains all the files (and the filesystem metadata)
dd if=/dev/zero of=bigfile count=6144000 bs=1024
# load the kernel module
modprobe loop
# assign loop0 to your bigfile
losetup /dev/loop0 /opt/data/bigfile
# restore 
partimage restore /dev/loop0 /root/aton.sda2.partimg-20071020.gz.000 

# mount your virtual disk
mount /dev/loop0 /mnt

#copy your files
umount /mnt
losetup -d /dev/loop0

Thanks to SR for the idea