How about bringing it inside the department?
Beyond that, I'm at a loss. Not knowing your environment, your culture, your people, your work product. But I will say this, for what it's worth: I've yet to have a bulletin board motivate me. (But, a well-deserved kudos, pat on the back, "you earned your keep today big time"....recognition!!! That motivates me.)
But...I'm a curmudgeon, so there you go. Plus I despise 'successories.' You know those stupid things I'm talking about? Pictures of eagles soaring, with captions that say "You can soar as high as your heart flies."
Gimmee a break. Maybe I'm too old, too jaded...but I'd much rather have a cold, hard dose of reality. Like a photo of a raccoon smooshed on the road, with lots of raccoon babies smooshed right along side, and the caption says "Momma ain't always right."