Have you considered 'roller stamps', like the one sold at novelty stores with fotprints on them? The might work well for wall, water, and, well, footprints...
Since most people likely use some sort of grid a better idea might be to have a markings on the side of the roller to help people line it up with their grid. and make sure that the roller is some multiple of 1 inch.
Roller stamps for long features is a good idea. I agree, simple mark on on the roller for alignment rather than clicking would be best.
Other stamp ideas, some of which have been said before
Ritual altar
Decorated hollow circle (spell/protection/summoning etc)
Campfire (living/dead)
Blood splatter
Chains
Rug
Spell effects (Bigby's Hand, Corruscating beams, etc) - I know these move around - but stamped on the board they at least give the players an immediate visual reference/reminder of what's been cast - and should look fun
Those are pretty cool. To bad I'm poor at the moment
Anyway, a "Cave" set might be neat. Stalagmites and Stalagtights type stuff. A cave entrance stamp like a door stamp. I don't know if a Pile of rubble would work or if you could just use a bunch of boulder stamps. A waterfall stamp might also be cool.
Also maybe a "Camp" stamp. Tents, firepits and weapon racks things like that.
At the studio we have received a suggestion for booby traps.
This sparked an idea for a whole set of booby trap stamps (DM's always love "Challenging" their players, right?)
So, What booby traps would you like to see?
The classic pit trap with spikes would be the first one included in the set.
Thank you all for the feedback and keep it coming.
I would do stamps that allow a GM to map his world as PC's explore it. Therefore, I would have stamps for forest ( tree ) mountains, desert, plains and hills.
I know I personally wouls use these, in conjunction with hex paper ( hex = 3 miles ) as PC's explore parts of the unknown world.
I would use the indoor ones on a battlemat. That would save alot of time, as my players hate to map things out.
What is the cost going to be on the next set of stamps? I went up to Games Plus to buy 'em and was shocked at the price. Hopefully the smaller sets mean a smaller price. In addition, having the stamp list actually on the box itself would be a good idea. I had to speak with the owner, Curt, whose a great guy, to find out what was in it and how it played in the game.