OK, but what does that have to do with networking? TCP/IP over USB requires extra software under Windows, and can be a pain under a *n*x. Firewire is made to do it.
Any kind of actual networking will do. It's not about file size--it's that you have to get a way for each PC to see the other one as a machine in a workgroup/domain/whatever, and share stuff. That basically means full, normal, networking. Your desktop surely has a NIC. A NIC in the laptop, and a crossover cable, is the best solution, unless you use a router (in which case plugging both into that, with a straight-throguh patch cable, is the way to go). USB is a horrible solution. What is your network setup, if any?
A temporary solution, though, if you won't need to do this in the future, would be to use a CDRW. Put all the files in a RAR or ZIP (RAR would be easier to spread out, IMO), and split it into ~400MB chunks. Burn, transfer, burn, transfer, repeat until done, then combine them and blow them back out.