What's available for online roleplaying?

[robkelk]

I'll start off by saying that I'm not interested in video gaming, either PVP or cooperative (which is why I'm not asking in The Legendary). What I'm looking for is a "virtual tabletop" - something that people can connect to and talk though a game, with a dice roller function that can handle more than just 1d20 or 3d6.

What's out there for roleplaying when people can't get together? What's good, what's okay, what's usable with external add-ons, what should be avoided, and what's out there that people know about but haven't used?

My criteria:

• Pros: Low cost, Presence of a dice roller where everybody can see the results, Ability for at least a half-dozen people to take part at once.
  
• Would be nice: Voice communication, Ability to show maps and other visual aids. If it has a text interface instead of voice communication, the ability to save the game log.
  
• Not wanted: Ads.
  

I currently have a static IP, so I can host a service if necessary - but I'm also interested in existing online services that would probably be faster than my home connection.