manipulator symbols
 

I was watching a tutorial and noticed that the instructor was changing the size of the manipulators (translate, rotate, scale) as he was working. I guess he was using a hot key but I can't find any info on how to size the manipulators.

Also, I was watching a behind the scenes video about the new King Kong movie and I noticed that when the guy selected an object to control certain facial movements the usual manipulators didn't appear. Is there a way to turn off the manipulator symbols so that when you choose an object to translate or rotate they don't appear? I figure the objects that the guy was choosing were probably the drivers in a set driven key set up.

the + and - keys will change the size of the manipulator.

If you just use the select tool (q) there are no manipulators when an object is selected.