Channel Hop: In an effort to attract interest in FX's new comedy-oriented spinoff channel FXX, Sunny will air its 9th and 10th seasons on the new channel. It's also worthy to note that The League and Legit will also make the hop this fall (Archer was supposed to go to FXX as well, but, instead, stayed on FX and went from airing on Thursdays to airing on Mondays). Read more about it here.
The Danza: Charlie Kelly is played by Charlie Day, Mac is played by Rob McElhenny, and recurring character Artemis is played by Artemis Pebdani.
Those dick towels they were trying to market? You can buy them, but don't Google them if you're on a shared home computer or on a computer in a public setting (read: library, computer lab at school, etc).
Greenman, which has not only been defictionalized, but is well on its way to cultural phenomenon status.
Recipes for "milk steak", a dish Charlie apparently made up in "The Waitress Is Getting Married", have appeared online.
And now fans have done the same for Rum Ham (not to be confused with an existing recipe for wussy, rum-glazed ham). It tastes pretty awful, but it'll get you good and wasted.
Dyeing for Your Art: Rob McElhenney gained 50 pounds in order to prove a point about sitcoms for season 7.
Jossed: A fan theory is that The Waitress's name is Nikki Potnick because she couldn't find her name tag at her high school reunion and Frank had stolen the "Nikki Potnick" tag. During his "Ask Me Anything" for Reddit, Glenn Howerton said in no uncertain terms that "the Waitress is NOT Nikki Potnick."
When series creator Rob McEllehny was asked a question about his character Mac in a featurette, he replied "I don't know... I just show up, say my fuckin' lines, and go home."
Charlie's play The Nightman Cometh was for a while actually touring various cities around Philadelphia with all of the original cast members.
Charlie Day revealed that Charlie's rat-killing speech in "Charlie Kelly: King of the Rats" is basically how he got his role in Pacific Rim.
According to Charlie Day, during a recent interview on Conan O'Brien, Danny DeVito has stated that he's up for pretty much ANY storyline the show might throw at him save for one topic: prison rape. Apparently, DeVito informed series creator Rob McEllehny that was the only type of shock plotline that he refuses to have anything to do with.note Offhand jokes about prison rape are apparently fair game, though. In season six's "Mac's Mom Burns Her House Down", there's a joke about Frank thinking that prison rape happens at nursing homes.
The writers of Game of Thrones were such big fans of the show that they ended up writing "Flowers For Charlie".
Rob McElhenny also landed a small role on LOST after meeting co-creator Damon Lindelof, who is a big fan of the show.