Is there any Linux application that can attempt data recovery for this purpose...?

All of this taking place on a single hard drive... my PC came with XP (thus, one big ntfs drive). I modified the parition table to split up the drive into 4 partitions: 4, 40, 35, and 1 gigs respectively. The last two have been formatted for Linux. The first two, on which I presume the majority of my data was stored, have otherwise not been touched.

Upon completing this, I remembered a file I'd like to have saved. Theoretically, that data probably still physically exists on the drive. Do I have any hope of getting at it?

Well what happened? What's wrong? If you just resized the partitions and didn't touch the first 2 partitions then why can't you access it's data? Are you getting an error? Does it not boot?

Hmm...Maybe you meant that you formatted the first 2 in the process as well.

Well, if that's the case there are data recovery tools out there. Most of the ones I know of are for Windows though (just go to www.downloads.com and search for 'recover deleted files' or something like that). Your best bet would be if you have another hard drive laying around, throw windows on it, and make the mest up hard drive the slave. Then run the recovery program on it.

Your biggest problem will be that if you didn't defrag the drive before repartitioning it, much of the data could lie in what is now your linux paritions and most of the recovery programs won't be able to touch those. I did use one recovery program a couple of years ago that could do this though, unfortunately I don't remember it's name.

Just do your best not to install or write anything to the hard drive until you get your file as once the data segment is overwritten, the file (for all intents and purposes) will be gone permanently.

Good Luck.