Tweak the evolutionary paths of random local species (that one's not necessarily budget friendly, but you could start with an ant farm), spook and/or abduct hillbillies, hang out with bigfoot, bear enlightenment, brighten the lives of lonely children, prove surprisingly susceptible to the common cold (wouldn't want to go through with this one all the way, but screaming and fainting when someone sneezes might be good for diverting theatrics), beam mysterious codes over little-used radio bands, build pyramids (small ones), impart psychic abilities, irradiate things, deliver fell warnings, pour souls into volcanoes (that one's impractical, I suppose)...