One warning and one hint from me for using rsync for backup/restore:

- If you have some packages which optify some parts from the rootfs (for example in my case I had pymaemo-optify) be sure to install this package in addition of the essential rootsh and rsync packages on the freshly flashed device ready to restore. Otherwise you will end up with full rootfs with 0 bytes free. You need to do this because otherwise you'll restore the contents of the dirs in rootfs BEFORE you had those dirs optified (on the next reboot with 'mount -bind') and you'll have real copies of all those files in rootfs hidden by binded mounts above them.

- And one hint: for quicker and more stable (not over wifi) restore procedure you can make one ext3 partition on some spare micro sd card and copy your backup there to do the restore with rsync.