Address is http://www.buzz3d.com The program is free if used for only 2 people chatting. For more than two it will be available soon, but then it will cost.
Anyway I've used it 4-5 times (on occasion for up to 2 hours at a time) with my son in NJ and once with my son in Minnesota--I'm in NH. Each and every time the voice clarity back and forth has been remarkable and the video does an excellent job of keeping up with one's motions--say you move your hand back and forth across the camera or count "1-2-3-4-5" as you hold up 5 digits one by one. It has detailed setup instructions. It is far superior to Yahoo's Instant Messenger and to the Intel program I used to use. And it has been very consistent. It is usable with XP's firewall and with other firewalls. It worked nicely through my Minnesosta son's router. It has 2 videos--you and the person you are calling. The size of these on a 15" monitor measures 3.5" wide x 2.5 tall. It is a British company.
If you decide to try it out, go to the site, go downs the left side to "Freechat and video chat" and click 'free download'.