re[Newbies] cover a deleted image??

Hi, in tidying up before installing Ubuntu Jaunty, I've misplaced a Squeak image and changes file that I would really have preferred to keep. Does anyone have any experience of 'undeleting' an image file under Linux? There seem to be utilities that will get back more common file types, or which can accept a specific 'recipe' to look for a user defined file type. If anyone has done this I'd be very grateful.

It's not anything terribly important, but there were quite a few hours of work in it.

Thanks for any suggestions, ...Stan