Check out this article on MTV.com that takes a look at a "real" R2-D2 unit created by the Bay Area Artoo Builders Group.
"Wired visited with the Bay Area Artoo Builders Group for a look at their fully functioning R2-D2 replicas (X-Wing Fighter not included). Maybe they’re not functional enough to navigate a starship, but the top-mounted dome swivels, the periscope rises, all manner of lights flicker, panels open and more. There’s even a panel with a built-in fire extinguisher! The $10K minimum cost is a factor, but being a fanboy often comes with a heavy price."
Check out the full article here and see the video below.