ran mkreiserfs and erased my ext2 partition!!!

[Patrick House <pathouse@uclink.berkeley.edu>]

I ran
$ mkreiserfs /dev/hda6

instead of /dev/hda5 (which was a blank partition) and it overwrote my 
ext2 parition with all my backup data without any sort of confirmation.  
Is there any way at all to recover this?  If i just convert it again to an 
ext2 filesystem can I use Midnight Commander's undelete function since the 
inodes shouldnt have been overwritten?  Help?