Recovering Passwords/Cookies from a Deleted/Reformatted Hard Disk

I'd like to know if anyone can point me to any applications or techniques for recovering cookies and/or passwords from a hard disk that has been wiped clean and reformatted. I took my PC in for servicing in April and the technicians ended up wiping it clean and reinstalling Windows. I foolishly forgot to write down a few key passwords, and have been unable to recover them with more conventional techniques. (I moved last year, so the email address I had on file with a few sites is no longer valid and I can't change the email info without having the password... urghh...)

Thanks.