Yoko Ono (artist, musician, widow of John Lennon)

I’m still reeling over @yokoono‘s apparent approval of a creepy OLPC ad involving her late husband, but I like her tweets, which tend to be the kind of things you’d expect Yoko Ono to tweet about, expressed as you’d expect her to express them (“VOTE NOW for a Department of PEACE,” “dancing,” and “is drawing a somersault to see the world in a bearable light”). She’s 75, but could teach a trick or two to celebrity tweeters a third her age.

Okay, which deserving superstars did I leave out?