These were so funny! I read these to my older daughter. These were her favorites:
"The past, present, and future walked into a bar. It was tense."
and
"A hyphenated word and a non-hyphenated word walk into a bar and the bartender nearly chokes on the irony."
The latter took us a while, but when we got it, we laughed pretty hard.
And I just had to share on Facebook, because I knew that my grammar-loving friends would enjoy it immensely! :-)