Clicking is bad
Clicking means there is a problem mechanically - software recovery program probably won't do the trick (unless as other suggest, you pay the big bucks and send the HD off to a data recovery company). One thing to try (and you may have tried it already) is to add it as a slave drive on another computer (if you dont have a 2nd pc, maybe a friend will let you do this on theirs) and boot from their hard drive and see if you see it as a second disk. Chances are this won't work since the clicking, but it may be worth a shot
One thing I have tried several times and it only worked once was to place the HD in a ziplock bag and stick it in the freezer for a few hours. Then quickly plug it back and and be ready to copy your data - if it works you probably dont have long to get the data.
As an extreme last ditch effort when all is lost anyway. You can try dropping the drive flat on the ground from a foot or 2 height. Chances are very slim but i've heard of a drive being accessed after doing that. Again, if it works copy your data quickly!
Good luck!
Glen M