What are options for free online mapping tools for running a 4e combat?

Google Drawing, part of Google Docs.  Use Windows Paint to draw some lines on your map, type in numbers and letters, then copy paste people's images onto the map and resize them to fit in the grid.  For instance, part of a map I recently used (the map itself is zoomed in 200% because I drew the map a little small):
http://i9.photobucket.com/albu...wing_zpsd4a7eedf.png
I set it so that anyone with the URL could go in and edit anonymously if they wanted.  I don't want to have to update everyone's position on the map, so I tell people they should follow the link, move themselves, and just post in the forum where they moved to (like A18 or wherever).
Edit: this works for any system that uses maps/battlemats, not just 4e.
This message was last edited by the user at 20:34, Thu 01 May 2014.

An easy tool for any map-based combat with a lot of movement is Ditzie. Very simple.
http://beta.ditzie.com/
You can get your own symbols/tokens in there as well.

You can post the map and people can adjust their locations at any time.

A shout out to Roll20.net. It has both free accounts and paid, but is incredible. It is a virtual table top (similar to maptools) and it is hosted online. No software to download and if you pay for it, you can a fess it from mobile devices. It has initiative and token ownership. Along with a virtual dice roller, etc, etc. it does not compete with rpol when it comes to forums though.