There are file-transfer USB cables out there... basically a USB cable that has firmware in it so that both your mac and pc will recognise it as a device, and allow you to transfer files across it. I think they cost about $40. I don't own one, but I've used on before and it's pretty slick. Make sure you get one that's USB 2.0; otherwise, it won't be any faster than a network transfer.
edit: here's one of them:
http://www.targus.ca/ca/product_details.asp?sku=ACC96CA