You've seen these droids before while watching the movies, but where can you find them again in the films? Here's a quick guide.
R2-A6, R2-M5, and R2-C4 can be seen serving the royalty of Naboo during Star Wars Episode I: The Phantom Menace. R4-A22 wanders around the Coco district on Coruscant during Attack of the Clones.
Those looking for R4-E1 and R3-T2 need look no further than Mos Eisley Spaceport, right around the Cantina scene, in the original Star Wars, while R3-T6 can be viewed on board the first Death Star. R2-X2 is in the Rebel briefing before the attack on the giant space station, while R2-Q2 can be spotted at the beginning of the film when Leia is captured, as well as in the socket of an X-wing Fighter at the end. Just who does he work for, anyway?
Finally, fans of R3-Y2 know that he's hiding in the Hoth Rebel Base scenes in the Empire Strikes Back, just barely visible as the Rebels realize that the Empire is on to them.
So, there you have it! Each and every one of these droids was designed by Lucasfilm for use on-screen in the Star Wars chronicle. Keep an eye out for them the next time you watch the movies!