I didn't mod mine at all but I did manage to cram in a 1TB Velocoraptor, 3TB XT, 2x GTX 670 FTWs, with an i7 960, a Zalman 9700 and a 1100 Tagan Power Supply.
Check out the video:
It was made at work using a Samsung Galaxy S3 using some app I can't remember. Forgot to mention the 2nd 670 was being RMA'ed when this build was made.