Getting username from Facebook id

If you have a facebook id or username, you can get their username or facebook id respectively by appending it to the end of this link:
https://graph.facebook.com/

About computers, in general

Doing some very basic hacking.. It looks like iOS6 doesn't allow modificationx to the file directories of actual apps, else I would be releasing some mad hack for iOS [that I created while I was still on iOS5]. However, I still have my Second Gen iPod Touch to save my arse, still being stuck on iOS 4.2.1 has it's perks.