A simple solution may be to just enable internet connection sharing (ICS) on one machine in your meeting. All you'll need is one machine with a wireless card, and a hub or switch. On the host machine (the one with the wireless card), enable ICS on the wireless nic and allow HTTPS and HTTP traffic. Next, connect the wired nic on the host machine to a hub/switch. From there, have everyone that wants to connect to the internet connect to the hub/switch (wired). Everyone should have access to the net as long as the host machine has access to the internet. It's an easy solution that requires one piece of extra hardware (hub/switch). Just make sure you turn off ICS when you are done as it assigns a static IP (192.168.0.1) to your wired nic.
Edit: If you only need one other person connected to the net, you can do away with the hub/switch and just connect the other machine to the host machine with a crossover cable.