Our group uses OpenRPG. It has better chat tools than MapTools as far as I can see, but a less feature-ful map. We use the text chat instead of voice, mostly because many of us find it easier to get into character with text.
I use Yahoogroups for my online play. Sure, it is not real-time, but I like the freedom to post from anywhere any time. I teach, so I usually post from 4 or 5 schools and as many computers a week.
I just cannot get blocks of time when everyone can meet, so Yahoogroups is my FTF substitute.
Somebody mentioned they use MapTool in their PBP game. How does that work? I was considering using it in a PBP game at one point by taking screenshots of the board after people describe their moves and posting them with the description of the combat round. Is that how other people do it?
Doesn't it allow you to save the map as a picture? I would have thought so.
Otherwise a screenshot (cropped appropriately; IrfanView could be used for this) is probably the way to go (though map size is limited to screen size then, otherwise it will be more work).