In our incredibly shrinking universe, I have found iChat Video to be an indispensible communication tool. I use it to work on 30 Boxes product design and engineering with Nick in Colorado and I use it to enable a more vibrant experience with friends and family.
For the most part it works flawlessly–fantastic audio as well as video that is quite good even when expanded to fill my 17 inch monitor.
There are can be hiccups. Often after your Mac sleeps or is idle for a while you need to exit and restart iChat to get a connection. Sometimes you need to “brute force” it and restart your router. I have even experienced an odd bug where iChat suddenly starts kicking you out of the service and after some hair pulling I discovered that changing the Preferences > Account > Server Settings > Port from 5190 to 5191 fixed it (odd I know!)
Be aware that because Apple goes for quality, iChat likes to fail (not connect) instead of delivering a subpar experience and this can be a drag. I have a friend living near Mulege, Mexico who is developing baja real estate and has a satellite dish but we have never been able to video conference until today.
Enter Skype Video. Since being acquired by eBay, Skype has been quietly improving and to my surprise we got quite a decent video chat going. There was some latency from the satellite but that was to be expected. It was exciting though, maybe akin to what NASA felt like in the lunar landing days, having the video appear after nothing but static.
[tags]ichat, ichatav, skype, skypevideo, ebay, mulege, bajarealesate, mace, macepicken[/tags]
No Soap, Radio! 
good to hear you have some positive experience using iChat AV!
I was a bit shocked when a friend of mine & I tried iChat AV and Skype video conferencing back-to-back – between Bangkok and Houston, Skype was the clear winner and I can only suspect it is because of the P2P algorithms at work. That said, iChat AV is reportedly higher quality within the states -I can’t vouch for this personally.
this test was between a 2.16Ghz macbook and a iMac (2007 model, GHz unknown) – last call was fairly recently in Feb 2008