I'd... actually there isn't anything I'd really like to do that is illegal that can be completed in 30 minutes, so I guess I'd just take a load of cool stuff from shops without paying and possibly physically assault some people who deserve it.... although most likely just the shoplifting stuff.
EDIT: A lot of people seem to be saying they'd kill people... Yeah sure, like you'd really do that. I mean its unlikely that there are that many psychotic-unemphatics capable of murder on Escapist.