baby arm
This phrase, recently popularized by the "Lee Corso has a baby arm" sign seen at the 2006 Texas/Ohio State football game broadcast, originated on the Ticket, 1310 AM in Dallas, TX.  A weekend morning show called The Rant, hosted by Gordon Keith proposed a hypothetical after a long discussion about Grady Stiles (the man with "lobster claw" hands that became a sideshow legend).  The hypothetical was as such:
Would you rather have a baby arm (an arm that is far underdeveloped on a full size person, which is a common defect), or a lobster claw?  

The lobster claw would be on a normal sized arm, so it's a normal arm with the claw or a mutant mini baby sized arm on a regular sized person.

Baby arm has become a generic phrase used by the staff of the Ticket as well as the listeners.  It is mostly a greeting, and has been championed most in recent times by BAD Radio (a show on the Ticket), although all hosts might spit it out here or there.  Dan McDowell, co-host of the BAD Radio show actually wrote a song about baby arm and performed it at the Ticket's yearly convention called Ticketstock.  It was set to the tune of Candyman.

In recent times, the phrase "baby arm" has been surpassed in popularity by the phrase, "have good and get give", which is a shortened version of "have good and get give on a get give Sunday with three times the catfish face fry", which was something callers Luke and Josh used to utter when they phoned the afforementioned "Rant" radio program.  Basically, the phrase is nonsense and part of a larger game known as bandsaw, the definition of which can be found on this very site.
"would you rather have a baby arm or a lobster claw?"

"Hey-what's up!?"
"baby arm!"