I see a lot of talk on Virtual Desktops, so I’m going to throw my 2 cents worth. www.fantasygrounds.com
The is cost involved, but in my opinion you get what you pay for. I’ve bought the unlimited license which lets me host and run multiple games…and doesn’t cost players anything to join.
I’ve successfully used it to host the following games
Basic D&D
Advance D&D
DnD 4e (it’s excellent for this version..as it handles all the little things, and actually speeds up the game)
Warhammer (1st and 2nd editions)
Savage Worlds (in which I ran Deadlands Reloaded)
Anyone else have experience with this one?