videoconferencing using linux / free software

[andy baxter]

A friend has asked me if I could find out about free software for 
videoconferencing. At the moment he just wants a general idea of what is
possible, but has also asked me if I could set something up for him.

Does anyone have any practical experience with this who could advise me 
on where to start looking? E.g. which software is actually worth 
investigating further. I've found the following page through google:

http://myhome.hanafos.com/~soonjp/vclinux.html

but there are so many projects it's a bit hard to know where to start.

Thanks,

andy.