Turn any surface, piece of paper, table-top, wall, or just about anything you can think of into a dry erase board by affixing a sheet of clear acrylic plastic.
And at 15$ for 30x48x.098 sheets in packs of 10 not expensive either.
This actually works, there is a DIY project here: DIY Dry Erase board
They went big, covering most of a wall.
How we can use this cheap technology*
Dry Erase + Character sheet = better HP tracking
Dry Erase + Battlefield = quick monster tokens
Dry Erase + Battlefield = quick fighter marks and character status effects
Dry Erase + Dungeoneering = Quickly marking off part of a tile indicating impassibility, obstruction, difficult terrain, or other useful markings.
And Shootin Bricks, since you like to use dry erase to keep track of the character stuff, you can lay out your graph on a thick piece of poster board or foam core, apply a sheet of acrylic, and not have to worry about accidentally erasing your lines anymore.
I'm sure there are dozens of potential uses for something like this.