If you're using Windows 7 you can find your wallet.dat file in C:\Users\(you)\AppData\Roaming\Bitcoin\

Put it on a usb drive or some other storage media before you format your computer.  Once you've formatted, reinstall the Bitcoin client and restore the wallet.dat file to the new location.

Nefanon, I don't think that's what's going on here at all.  If someone's funds are being held without apparent cause I think they have reason to be concerned no matter how reputable the exchange is.  I've read all over the forums that mtgox has requested ID from people in several instances, sometimes in accordance to their TOS - sometimes not.  I've read they've been vulnerable to attacks and I can see why people are leery of sending them their information.  Another reason people might be reticent to send their ID is because they do not want their real identity linked to their Bitcoin balances in case there is ever any government snooping at the exchange.

Would this also be available in the form of a USB drive?

No disrespect meant, but what makes you reputable enough to send cash TO?  Perhaps the best option would be to find someone locally who is willing to buy your BTC for cash.

Wow, wish I'd read these restrictions sooner! Been here a week, mostly lurking and reading, but surely I could have knocked out the 5 posts by now.  Oh well, I do see the reason for it.