Well, depends on what you expect.Battle Map
is kinda simple, but designed exactly for combat stuff. It is made in Flash, tho, and is designed to assist a tabletop game, so you'd have to make screenshots of it and upload them somewhere. If you choose it, I think I can make the process a bit easier - notably, create a "Flash Projector" application, so you won't have to cut the webbrowser panels from the screenshot, and maybe make an easy uploader for you somewhere on my part of Urocyon webspace. Other thing that might be worth pondering is using some screen sharing software, for exaple Ustream or Livestream, to show us the mapper screen instead of posting screenshots.
These two, and most of the other applications below seem to be map designers, so we'd need to either make a player/monster tiles for them, or make a map once and then use Photoshop, Gimp, or any other image editor to draw symbols on top on it.http://www.yeoldemapmaker.com/
- Semi-Official WotC one?
But MapTool ( http://www.rptools.net/index.php?page=maptool
) is hyper awesome. Even allows you as a GM to set up a server and rest of us to connect to it and see the map live.
It's a little complex to set up initially, but I can help you... and it allows for even such cool things as a fog of war, so you can have a full map laid out and us players not seing it, a bunch of available tile sets, and ability of importing custom images, so we could (if you wish so) use our avatars or other symbols for player tokens.
Again, depends on how much functionality do you want