I haven't the faintest idea where to look for this, so I thought I'd ask here. Currently my two main 'luggables' consist of the HP nx9420 and Macbook Pro. Both have 17" screens, both have 2.16Ghz Core Duos and both have X1600's. I was at a friends house the other day with us working on these two machines and later we played BF2 with the Macbook running in Boot Camp, and in fact the hardware spec is surprisingly playable for games. So I figured I might as well stick CS:S as well as BF2 on these machines. So I'm looking at sound and wondering if there's anything out there which can work a little of that X-Fi magic over USB or Firewire. I'm looking for better headphone modes and CPU offloading if that'll help push framerates up. If it offers better sound, that would also be a bonus. Does such a thing exist?