Here’s an article (http://www.mercurynews.com/mld/mercurynews/sports/baseball/mlb/san_francisco_giants/15062194.htm) [EDIT (3/26/2010): dead link] with some vocabulary used by San Francisco Giants’ commentator Mike Krukow.
I like Grab some pine (Go sit on the bench) and brain-dead heaver (“a pitcher without finesse”).
I’m not into sports myself, but I like the colorful language of baseball announcers. On those rare occasions I see some of a game that someone else is watching, I’ll start cracking up at some of the things the announcers say or I’ll ask “Did he just say X?” People actually into watching the game often don’t notice. John Madden doing American football announcing is great, too. He may have coined the term cankle (calf + ankle), describing players whose calves go right down to their ankles.