And that of course is exactly the way to do it. If your PC hasn't got an Ethernet port (pretty rare by now, I should have thought) Ethernet cards are as cheap as chips. Your Mac will have Ethernet, and the network will run at speeds that make both Firewire and USB look slow.
Yes I have both Ethernet ports on PC and Mac and they switch files ok, but sometimes drop out, so got me thinking if FW or USB would be better?
Get your network sorted for 1Gbps.
How Chris? not great at all this stuff
I should point out that I'm on 10.7.3 OS X Lion and Windows XP Professional - so no Windows 7 or 8 for me..