I've been snapping some photos from around JPL over the past months or so with all the excitement about the Mars rovers. Two big sandboxes are in the JPL mall. Reporters are always using them for backdrops.
The banner hanging at the main entrance to JPL (They've since added a panel for Spitzer, née SIRTF, too)
Sandbox with fully deployed model
Sandbox with landed model
The main signboard out front with all current JPL missions. You can see we've got quite a few, besides MER.