wedgeski
Adventurer
Great bit of software, really user-friendly. Scaling is pretty easy on gridded maps, simply by setting the units to inches and counting the squares in the image.I use PosterRazor. You need to know how large it should be at the end, but it works well and lets you print it out on a regular printer.
The only way it could be improved would be if you were able to select which of the tiles to render, rather than having to avoid printing dead space on the map.