You can forget about Firewire.
Ethernet would be best, it should be Plug-n-play.
You could setup an ad hoc Wi-Fi:
1. Click on the AirPort icon in your menu bar. From the AirPort menu, select Create Network.
2. Click on require password.
3. Click on OK. The AirPort icon in the system menu bar changes to a little computer in a gray signal field.
4. Other users that you want on your ad hoc network can now select the network that appears in his or her AirPort menu, they enter the password you set.
I personally use an Airport Express
. It's $99 and very portable. It's easy to setup a wireless network and if internet is available it can be shared to all wireless devices (iPhone, Macbooks, etc)