I know you've been waiting for this—don't deny it. Finally, R2-D2 can be yours, in your own home, and for only $119.95. Fully functional, R2 can roam around and obeys over 40 voice commands (please refrain from asking him to project Obi-Wan please). He also plays children's games like tag with an IR sensor that can be set to detect motion (which can also be set to sound an alarm for a watchdog effect). Available at Hammacher Schlemmer.
R2-D2 Robot Product Page [Hammacher Schlemmer]