There is a live chat button about in the middle of your screen on the right hand side if you play through Facebook. Would like to see more players there, especially Pro Bowlers. Anyone wishing to talk to another team outside your guild, here it is!
Live chat
Notice I didn't use my potty mouth? lol
I don't have a live chat button and I play on facebook
I've heard this from a few ppl Guest, if not in full screen there is a tiny tab under suggested games and gameroom download tab. You also can't see it through a mobile device like phones and tablets.