That actor that was in the original few Star Wars movies, has passed away. There was an interesting article on him, on the BBC web site. He was 3'8" tall and was the only adult that could fit into the robot. They couldn't use child actors for some reason.
At first, he didn't think he wanted to take the part because he was going to have to be in the robot. But apparently George Lucas could not find anyone else to fill the role.
I had a friend who saw R2-D2 as his favorite character. It's amazing how much personality can be created with whistles, beeps and wiggling and bouncing around. Kenny Baker pushed levers to move the droid around and his body to rock is from side to side and so on. It wasn't his only role but probably his most memorable.
This looks like the BBC article to which you referred:
http://www.bbc.com/news/entertainment-arts-37076140