ESI Design (requires Flash) describes their exhibit design firm:

ESI Design is one of the world’s foremost experiential design firms — we create physical and virtual spaces for people to interact, exchange ideas and learn from each other.

Their clients are:

museums, retailers, corporations, real estate developers, parks, hospitals, foundations and so on.

Haven’t actually seen any of their exhibits. They are located in New York, NY and seem to have exhibits all over the world.