I’ve not used virtual tabletop software in my games. I’m a sit-around-the-table kind of guy. However I have to admit the sheer connectivity via skype and google hangouts is drawing me towards possibly looking at running online games. I think for 4E tabletop software there are some kinks to work out. However stuff I have thought about before will likely never see the light of day given the edition change coming.
I’m curious how the development of the official DDI Virtual Tabletop will go. Sadly, I guess the 4E support for that will evaporate. But with a looser, gridless system possibly in the works for DnDNext, this might get more support. Dread gazebo put up a nice old beta tutorial on his blog.
There are some other paid versions out there like such as the one at Fantasy Grounds. I’ve heard some give the software positive reviews and it looks pretty nifty. Typically I shy away from trial versions, but I might give this a spin. They also seem pretty committed to updates for the program too.
While possibly not as full featured as others out there, you’ve got Map Tool which is free. A bonus in my book as you can try it out without having to worry about any hassle with a trial version. I understand quite a few folks have used and enjoy this for a while now.
Something else on my radar has been the Roll20 Virtual Tabletop. A few things I like is that it is web based. Also while the program is geared for 4E, it is also system neutral. A plus with the new D&D playtest on the horizon. They’re currently in closed beta, but I’ll be keeping an eye on how they progress. It seems to have some potential.
EDIT: As expected I just scratched the surface. There are a few other programs out there that folks have brought up. I'll just provide a list of the links here:
Gametable Project - a java opensource program
Tabletop Forge - that utilizes Google+ hangout
d20 Pro - a paid program but has a 30 day free trial