So what is the ultimate d20 gaming accessory?
Jon, alongside whom I play with in Jeff's game, has these nifty plastic frame thingamjigs that you can place on a battlemap. They are the outlines of effects of various radii. They are extremely useful when you don't want to have to figure out the size of an effect in the middle of a fight. On the other hand, they are kind of floppy and cumbersome. They are cool, but I don't know that I'd call them the ultimate in gaming accessories.
What I would find to be the ultimate accessory would be something that would make it simple to keep track of a wide variety of status effects and how they interact. My character is under the effects of Bull's Strength, Haste, Prayer, Protection from Evil, and the Inspire Greatness bard song, but he's just been dazzled and knocked prone. I want something that will allow me to quickly get the sums of the modifiers to his attack rolls, damage, AC, saves, etc. That would rock.