very very similar to pool hopping
. get thee
to a fairly big ass bus stop
, one where many busses meet. pick a bus
. ride it
. get off when you get bored
. choose another bus. ride it. get off
when you get bored. repeat.
this is actually a great, and cheap way to spend a day, as well as travel the world. it can be done with city busses or even greyhounds. with the former, i suggest a daypass or some other kind of unlimited bus pass, and the latter might prove to be awfully expensive.