USB displays but cant be used/accessed

Hello,

I have a problem with a USB drive and I cant find anything on the internet. I think I may have screwed something up by possibly pulling it out without safely removing... Now when I insert the flash drive, the light flashes on the drive and I see Removable Disk (G:) in My Computer (Vista 32bit) but when trying to open it, I get 'Please insert into G: etc etc...' Any action in My Computer, e.g. right-clicking properties on the drive or double-clicking it takes forever to work.

I need a way of either accessing the drive to use or being able to reformat it somehow so I can recover it later. Or another method if there is one.

The USB is a Verbatim Store N Go 4GB, a fairly common one. It contained a lot of important work from the last 3 years and was in the middle of backing up one computer onto another, so I have none of it. It does the same thing on any other computer I try, running XP or 7. Please help?

I tried safely removing it but it says it is in use.

I tried chkdsk but it displays as RAW formatting (which means it's screwed itself over already)

If I start the computer up with the USB in, it takes 10+ minutes to load what normally takes <5 secs (one of the screens before Vista itself loads, and before you can choose which drive to boot from.) I give up after that.

I'm going to try and reformat it as best I can, if that doesnt work what do I do?