Graffiti. Everything! >_<
Oh wait, you said if it was my last day, then never mind about the graffiti that would go bad, lol.
I would send a lot of ideas out to the internet, maybe ask someone who knows how to code to set up a program that would keep sending those ideas after I'm dead. Basically I would be dead, but still alive.
Donate to as many sperm banks as possible What? I have to pass on my genes somehow...... :P
I would say something else, but I would get a bunch of crap for it. Though I already said it in another thread.....
Edit: Also, I would play the song of time to go back to day one. :P