I used to do a mixture of most of the things already said....
Look at nice sisters, fantasize, pass notes, look at my mates and try to crack them up!!!! I also used to look forward to the fellowship afterwards too!
Occasionally, I'd listen!!
For the really boring public speakers, I used to play Theocratic Bingo... if they said 'theocratic buzzwords' 5 times or more I'd get a line. I always wished i had the balls to shout 'House!'