Eminem.
Not an actor, but still… I don’t think he could have been any clearer (third story down):
I had a crush on him when I was younger but I was too young to understand the significance of the size of one’s member and now that I know I am too old to care about his.
You have a guitar. I have an upright bass.
Guitar or bass, if all you are doing is strumming it yourself…
I’m just sayin’.
A clear limitation of the metaphor, no question - but the point holds. And I prefer to play my guitar in a combo, anyway - but don’t know if I am ready for the metaphor to stretch into group situations, either! 
And **Miller ** - your upright - doesn’t that get painful after a few hours, like they warn about on Viagra ads? 
Hey, I’m not a snake, I only play one on a message board. Maybe you should send Miller a link to that youtube video of the Tielman Brothers, so he can see what that guitar player did with a stand-up bass.
Apple doesn’t fall far from the tree, eh? Heard his old man was a douche too, from David. Wait a minute… .
[Kirk/]“No more donk donk!”[/Kirk]
Only on Straight Dope would a post about a celebrity’s tell-all book derail into a discussion of snake morphology and celebrities with small penes.
I always wanted to use that plural. Thanks for giving me the excuse.
If you like that, note that the snake’s equipment is referred to as the hemipenes.
If the snake was named Enrique, would they be demihemipenes?
My 14,000th post, and it was a bad joke about reptile wangs. :smack:
Howard Stern. I was gonna say he’s not an actor, but he did make a movie.
Donk: “That water sure is cold.”
Donk donk: “Deep, too.”
Hey, it’s only the big stars that get the solos.
Then there’s that probably apocryphal story about the time the Cassidy Brothers were all at the Brown Derby and got into an argument over who was most bodonka Donk and it ended with Shirley Jones pulling out just enough to win.
But I may have this confused with another "
Shirley Jones winning a penis contest" story.
OK, just one more comment on the Cassidy clan’s alleged tumescent splendor:
I just saw a rerun of “Hawaii Five-O” in which Jack Cassidy plays a character named “Morwood.” I don’t know that “wood” back in the 1970s would have been recognized as meaning “erection,” but, in today’s vernacular, I could just imaging Cassidy saying, “Yeah, that’s right. I am Morwood, and I have more wood.”