I've got one!
On the way to my bachelorette party, my friends went past an Ace Hardware that had the following sign:
"Free Butt Rub With Green Egg"
When they got to the party, we all discussed it and figured it out. Apparently a "green egg" has something to do with a grill, and "butt rub" is BBQ seasoning for meat.
Cracked us up for a while, though.
Another friend told me a story from when she was a teenager. Another friend of hers had gotten fired from a small drycleaner's, and begged my friend to come help her get revenge. (Right after the firing, they'd put up a sign that said "Mature help wanted") Friend's friend decided to have a little fun with that, and roped my friend into climbing on top of her truck at 4 AM and rearranging the sign to say "Help! Mad Turtle!" (They couldn't come up with anything else.) lol