home videoconferencing with a Mac user

[Seth Gordon]

My mother (in Oakland, CA) uses iChat AV to have video conferences with 
my brother, sister-in-law, and nephew (in Chicago), and they want to do 
the same thing with me and my family.  Two problems:

(1) iChat AV seems to be a Mac-specific service.

(2) Neither of our laptops have FireWire ports.

Any ideas (preferably ones that don't involve spending a kilobuck or two 
on a PowerBook just for the sake of the video conferencing)?