In order of safety:

1) Use a live CD (like Knoppix as AnotherScott suggested) and attempt to mount the drive with it and copy everything off with rsync or even ftp. Data loss unlikely, cost free.

2) Use [link|http://grc.com/spinrite.htm|SpinRite] to low-level diagnose and repair the drive. Data loss could happen, cost about $90. (When I had a similar problem, I downloaded an eye-patch version to see if would work on my problem, then gladly spent the money for a legit copy.)

3) Send to a recovery service. Data recovery likely, cost likely into the $2-3thousands.

LUCK