The World's Largest Wargaming Table
I'm a fan of Timothy Hutchings's work.
His The World's Largest Wargaming Table is very striking. I love how it starts as a blank landscape and becomes populated by gallery visitors playing with it.
His cardboard works, which range from formalist studies to large-scale models, are quite interesting, too.
Hutchings also runs PlaGMaDA (The Play Generated Map and Document Archive), which I blogged about earlier.