While this may not be considered "useful", it definitely falls under the umbrella of "AWESOME". Use the coupon code TECH20 (expiring soon) at Skymall to drop the price down to $159.99.

R2D2 obeys over 40 voice commands and navigate hallways and can play games like tag using an infrared sensor to search for people in the room. Freak the dog out and impress your friends at the same time.