data is not gone even after it is overwritten once.
granted, it is EXTREMELY hard to recover, and will never be perfect.
but you can use magnetic imaging and stuff to recover the data, if its that important.
and i would suggest some service you can mail your HDD to to recover the data, or even better, one you can take it to yourself. they will probably be able to get some if not most of it back.
P.S. HELP ME IN MY THREAD! I HAVE NO SOUND!
And above all else this, to thine own self be true.