External HD Stopped working... AHH!

Hello. So i've bought a second hand 250GB external HD a few months ago, and it's been great, i've stored all of my music and movies and things like that on it, also some of the work i've been doing. The idea was that i could back everything up, and clear heaps of stuff off my iBook..

However, it was working perfectly until a few days ago, and whenever i plug it in i get an error saying something along the lines of "This drive can not be recognised by the computer", i've tried it on two other macs as well, and get the same thing. If i go to the disk utility, I cant verify or repair the disk, because an error of sorts comes up. This is a cause of great concern to me, because i really dont want to lose the stuff I have on there. I haven't dropped it or anything, although I have carried it around in my bag, about a week or two before it stopped working.

Apart from it not being recognised, it seems to be fine, it powers up, sounds normal and everything like that. Which leads me to believe the enclosure is fine, but not the hard drive.

So, does anybody have any idea of what i could do? I've been told by friends to just clear the HD, as its probably bad sectors, then itll work again, but I would prefer having a broken HD, with everything on it recovered than having a working HD without my music and work etc.

Here are the specs:

Enclosure Brand: Pleiades
Enclosure Model: PD-FROT
Enclosure by: Macpower
Hard Drive by Seagate

Thanks for any help.

Don't reformat it just yet...

Have you tried running it on a Windows machine? Try running it through BootCamp or Parallels (assuming you have them installed). It might take Parallels to recognize the drive, so give it a few minutes.

Also,

What filesystem format is it? (NTFS/FAT32/etc...?)