I have the Macbooks serial number and all information located on the box / receipt.
Only problem is that this computer was stolen in late 2010 and I filed a Police report at the time but recent information has brought this computer to my attention once again, but on a different level, I have some very expensive data on this laptop and will pay UPFRONT for its recovery!
The NSA has all this information. Write a nice letter to them and explain you'd like you data back. Be sure to include the serial number so it more easy for them to find. But if you don't have that, just give them your cell phone number and they will have everything on a disk for you within an hour. No worries!