undo a delete?

[bradhtc]

Ok, I have a 4 gig memory card and somehow a 2nd DCIM folder was created (on the card, not the device). It was identical to the 1st DCIM folder, and had exactly the same photos in it. Since there were 600+ pics in it I figured I could save some room on the card and delete one of them. BIG mistake. Now all pics are gone from both DCIM folders (only one DCIM left). The remaining folder was completely empty. Tried a backup/ restore but I didn't back up the DCIM folder on the card I guess because I can't locate it when trying a restore.
I have an Alltel touch anyone know if it's possible to undo that delete, or restore the files? They are pretty important to me (should have transferred them to my PC!!) so I am willing to explore almost any options. Thanks.
BB