Microsofts SharedView has been around for awhile now and at this point is in Beta. Scott Hanselborg posted about the tool just recently and I finally gave it a spin yesterday with another coworker.
I was very impressed with the smoothness of the application and I really loved how each user was given their own mouse cursor with their name attached. They were not controlling the session, but they were allowed to move their cursor around. This is very nice to have because you can see what everyone is looking at when they're talking. Very nice.
I know there are many other tools out there, but I think this one might be a one for Development teams to embrace. I've used RealVNC before for Pair Programming sessions at previous clients, but sometimes I found it choppy and the display was horrendous at times (depending on network latency). I didnt encounter these issues with SharedView at all.
If you're looking for a new remote tool, or maybe you're just trying to show Mom how to burn a CD of photos, check out SharedView.
If you realize SharedView is not for you, check out some of these other collaboration Tools (some free, some not-so-free):