Problems With External Hard Drive

Hi, I really could do with some advice about my external hard drive which seems to have stopped working. It does not appear in My Computer, and doesn’t appear in Disk Management. It was working fine last night but seems to have packed up. It is a Toshiba 3.5 80GB one, I can hear a clicking noise coming from it, but just nothing happening when connect it to the computer!

Hoping someone can help!!!