WD My Book has ceased to exist!!

I'm in dire need of some help here..

My external WD My Book Essential has decided to go elsewhere!

I have been using this for a couple of years with no problems at all until 2 days agao when it started unmounting itself sporadically from my desktop. This set off alarm bells so I purchased a new 1.5TB LaCie drive to back the whole thing up. By the time I returned from the store, the old drive is now not mounting at all or even showing up on any of the disk utility software I have. (I'm using Disk Warrior, Tech Tool, MacKeeper, Mount Me!, and Stellar Phoenix)

Can anyone advise me how to get the data back from this drive? I'm a musician and have have about 20 projects that I'm currently working on on the drive, plus all the usual media (iTunes, Movies, photos, Etc.)

All advice welcome as I'm starting to panic a little bit!!!

First step: check your cables. Power, USB. Try another cable. If all fails you might be able to remove the drive from the case and put it into another case. Emphasis on "might".