Hmmm seems interesting, does the 3G video calling have a standard someone can point me out on. Also isn't this very carrier specific, would some carriers outright not support this capability. Seems like a worthy endeavor but it would seem that even facetime is more a P2P/ IM component than an actual Phone stack component. Now the good part is that this can be an actual usable component of the VoIP part of the N900, But VoIP video calls would be more flakier than regular SIP based VoIP, trust me I know since I was using VoIP over 3G for 6months and although all the benefits of having a bunch of calling features and paying as little as $5-$10 a month weren't worth it in uptime. It just wasn't worth it on the N900 because it was highly unreliable.

Lastly, call me old fashion but I am not big into video calls ... but having the option of using it on a whim would still be cool to have.

Enjoy:

http://en.wikipedia.org/wiki/IP_Multimedia_Subsystem

So Im in the Exclusive club here... nice!