Apple's site. This would have been so helpful for the family tech support and whatnot, and probably easy to implement under the Apple Remote Desktop/VNC stack; why would Apple drop it? Turns out it's not dropped so much as relocated. The Finder feature page now indicates that "[by] clicking on a connected Mac, you can see and control that computer (if authorized, of course) as if you were sitting in front of it." Sounds like what iChat loseth, the Finder picketh up and runneth with...eth.