Hey Reaper,
I've tried the following online tabletop interfaces:
Openrpg
WebRPG
Klooge
ScreenMonkey
GRIP
They all have pros and cons, but GRIP is the best one I've used. It incorporates a "character sheet markup language" which can be used to automate most all game mechanics, and it requires no central server to play a game. The "CSML" alone puts it ahead of the rest, though it takes a little time to get used to it.
Luckily, there's a great user community on Yahoo where anyone can get the help they need to get their own game up and running:
http://groups.yahoo.com/group/griplist/
Drop by this group if you're at all interested. GRIP is a Quicklink/RPGRealms product (yep, same as T20), and there's even a Traveller version of the software.
The software for players is free, and the GM software costs $35.00, but the vendor offers a 60-day free trial (fully functional) - plenty of time to figure out whether you like it.
Here's the site where you can download the GRIP trial version:
http://www.rpgrealms.com/GRIP/gripprod.html
If you'd like help getting a game going, testing the software, etc., I'm willing to lend assistance. Just email me.
- Milo Holt