I've never seen one, and judging by the fact that my university had an actual masters degree in data recovery, I can't imagine that anyone with the skill to write data recovery software would want to give it away for nothing.
Not that i'm promoting anything, but if you look in the "right" places you may be able to locate said programs depending on if someone out there has one and decided to "share" it...about the same way people can get full programs out there that charge money (e.g Nero), but I'd say a type of data recovery would be harder to locate but 1% possable. Also to contradict myself its usually best just to pay if its something that you really need than to locate a "shared" version for obvious reasons. [edit] I swear that doesn't seem to make sense anymore.
If there are indeed any good data recovery programs are indded "out there", you should realise such a program might not be even available to the public because it might be used in an abusive manner.
Are you talking about file recovery, like recovering files that have been deleted? There's two that I know of. PC Inspector: http://www.filehippo.com/download_file_recovery/ Recuva: http://www.filehippo.com/download_recuva/ Granted you're gonna have to recover the file as soon as you delete them or else these programs will count it as garbage data and un-recoverable. They are both decent Freeware in recovering files but if you want the best then your gonna have to pay.
Sorry for being late to this thread. There are many free tools for recovery. They are not Windows based which may bother many. Search for Ubuntu Rescue Remix. Ubuntu Data Revovery Information week as a good article on data recovery. Open Source Data Recovery Tools To The Rescue You can get really deep with Sleuth Kit. The tools are out there, just not Window based. I have used these tools to recover data from a drive that was formatted over twice and a changed file system. Another kit is the Helix forensic disk. A complete system on a bootable disk.