Varies. Might be eating my dinner, or watching tv. A lot of players take a lot of time to act, so the action generally runs a little too slow for me, so I'm able to do these things and still follow the game.
It also depends on the game I'm playing. If it's money worth winning, then I concentrate more. If it's loads of entries like a freeroll or play money, then I'm simultaneous in what I'm doing.