Paraprosdokians.

Just discovered this fascinating word.
"Figure of speech in which the latter part of a sentence or phrase is surprising or unexpected, frequently used in a humourous situation".

Where there is a will, I want to be in it.
Light travels faster than sound. This is why some people appear bright until you hear them speak.
War does not determine who is right - only who is left.
Evening news is where they begin with "Good Evening", and then proceed to tell you why it isn't.
To be sure of hitting the target, shoot first and call whatever you hit the target.
Etc.

Great word! They use this excessively in 30 Rock.

The form of the word didn't look right at all to me for the name of a rhetorical figure.

And it seems to be a recent invention, badly compounded from two Greek words by someone who doesn't know how Greek compounds were formed or rhetorical figures named.

The Wikipedia page mentions that piece and says that the term occurs in four different Greek writers on rhetoric, c. 100 BCE - c. 200 CE, but Casselman had already shown that Demetrius's de Elocutione doesn't actually use it. The other citations are all to hardcopy of texts not available on line and I strongly suspect they are equally bogus.

Thanks Vinny, now I am better informed.

I've never heard it before, but something to add to the list. It rolls off the tongue, just have to wait for the chance to use it

She was a good cook as cooks go, and, as cooks go, she went (H H Munro)
Time flies like and arrow; fruit flies like a banana (anon)
How to become a millionaire: start as a billionaire and buy an airline (Richard Branson)