I made this because my roof leaked during a storm and fried my old mac keyboard. I took my 256 mgb drive and replaced the case with a dremel, 2 keys, and some hot glue. I really like the way it turned out and I hope you do to. Take your time with making yours and it will look really nice.
Hope you like it!
Note: The following Instructable was my inspiration: http://www.instructables.com/id/Custom-USB-Drive---Project%3a-Enter-the-USB/