Playing around with GIMP, I created templates for square grid and hex grid maps that I can use for my Chainmail Arena game.
They're large size images. If I use this on Roll20, for example, I can post them there. If I use RPOL.net, I'd need to host them somewhere else and include image links in the threads. Google Docs will probably be my host of choice if I do that.
Here's the first test map, a simple circular arena with a 'thunder well' that randomly shoots out bolts of lightning around the arena.
15mm Sci-Fi Paramilitary Police....
11 minutes ago