Recover My Files (
http://www.recovermyfiles.com) is used to locate deleted files, including Microsoft Outlook PST files. Once you have recovered a deleted PST file then you will be able to open it with Outlook and get access to all you mail and attachements (please note that you may first need to run Microsoft's ScanPST on the file first).
Recover My Email (
http://www.recover-my-email.com) is used to recover deleted email messages from within a PST file. You run the program, point it to your existing PST file, scan the file, and recover your deleted messages.