There's many ways you can transfer data. The easiest (and maybe the cheapest) is to use a network card. You simply connect a cross-over cable between two network cards, and you've got a simple network wired.
Set up the cards with TCP/IP, using manual addresses, (one will be 192.168.10.1, the other 192.168.10.2, both with subnet masks of 255.255.255.0) and they should see each other. If both cards are 100 mbit, you'll be able to transfer the entire hard drive, if you wish, in a matter of about half an hour. If it's 10 mbit, set it up to copy and go to bed or watch TV or something... ;-)
Crossover cables can be purchased rather inexpensively at http://www.computergate.com You can also get NICs there if you need them.
(Computer Gate is one of the cheapest places I've found to get network cables. They're equal quality to what I have assembled myself, if not better.)