We all should be aware by now that if we're watching this event live there will be a PLETHORA of commercials. Between commercials I generally watch something on my media player and mute the TV. Tonight that will be Top Chef. What do you do?
Well for a live event the commercial breaks are only 1 minute between rounds. How much can you really do? If you're talking about the massive commercial breaks during the pre-fight pageantry, i'm usually just listening to the audio at that point anyways and watching / doing something else until the fights begin.
I play some Xbox. I like to play NBA 2K franchise-mode games with 12 minute quarters, so I can usually knock out a game or two during these free cards.
Read fighter's bio/record, check twitter/boards... Oh and of course piss and grab another beer when necessary.