That happened to me not too long ago, about a month ago. I was working on this monster, spent soooooooooooooooooooooooooooooooo much time on it and it dissappeared. i went into a state of depression and gave up on maya til now. I hadn't been to this site for quite awhile coz of that. I wanted to curse the world! haha
been getting into premier during the time, but I think im about ready to get back into maya. And the data recover program only works if you dont reformat your computer. When you reformat, most of the data gets wiped out and u can only retrieve some files. The moment you save stuff on the hard drive, the back up files get over written. So if your hard drive ever crashes....DONT i say DONT do anything to it, swap it and then extract the data right away. I didntknow about this til after i had fry's do it for me. They only got my useless porn and video files! So when i reformatted, i looked into the other hard drive and it wasnt there!! Stupid! So a friend recommended me the data recover programs and i used it, it didnt scan my projects. So the end of my sad sad story.

And....now I know the true purpose of partitioning.