Any computer experts out there?

Okay, so I have a Toshiba HDDR160E01X external hard drive and it has always treated me well. Only about 20% of its capacity is being used, but over the past couple of days its started to take significantly longer to load (with certain particularly large files giving me that dreaded "Not Responding" message), and it is now making a very discouraging "ticking" sound as I click into a folder. Every now and again, I hear a beep as well.

For the moment, all of my files still seem to be on the drive, however every once and a while a "could not access this folder because of an I/O error" message comes up as well. I'm doing a scan of the hard drive to make sure that there aren't any virus or whatever, and so far there doesn't appear any severe problems.

Basically I've already gone through the whole hard drive failure thing before, and on top of it being a massive inconvenience, it's a heart breaker as well. There are loads of photos and self-made graphics on my computer that don't exist anywhere else. So I really hope this isn't my hard drive crashing. But does anybody out there have any suggestions, on top of "back everything up"? I'd like to know if there's a solution to this problem that I'm not aware of.