Did you try Spinrite? I've done it on some downed Tivo drives and I was able to get it to the point that it was usable for another 6 months.
I had an external Mac HDD that failed recently. I used Spinrite to recover it to the point that I could get at least half of the data off before it tanked again.
You'll need a PC tower because it's a PC command line program that boots off a floppy. Or you could burn to a CD. It's worth a shot.
Caveat, it can take several days depending on what level of recovery you use. I've used the lowest level on the worst drives with some level of success.
Even as a converted Mac guy, I highly recommend this to anyone. In fact, Spinrite is probably the only reason I keep a spare PC tower around.
http://www.grc.com/spinrite.htm
