I'm gonna assume you mean like, if right now, our 24 hours started. In which case, I'd just sorta mope around real pissed off. I live like 20 miles from all civilization, and I can't drive, so I'd wind up spending my last day sitting around waiting to die. I wouldn't even be able to say bye to my friends and my girlfriend. So, yeah, my answer isn't incredibly inventful, but in all honesty, I'd just sorta wander around 'till I died.
I'd watch both Star wars 4-6 and Indiana Jone (first three) to see which is better. And then I'd watch that 70's show reruns. And eat chips and drink Dr. Pepper.
kill the jonas brothers, kill klausehouse, kill the 420 guy, call obama a nigger, take a piss in canada, and get in a commited relationship with zophia.
Or do we get to pick? I mean if everyone is gonna suddenly die from an asteroid I'm sure I'd handle it differently than if we were all gonna suddenly just drop dead.