A friend suggested I put a sign on my bike to advertise EveryoneDelivers.com. It was very simple and inexpensive to do. I made a sign using inkscape, took a PDF to kinko's and did a $0.50 color printout with a $2.00 laminate sleeve. That was zip-tied to the bike bucket and it's done. Now that the sign is on my bike, I'm aware of just how visible my bike is being locked up outside and how many places I take it in a normal day.
This photo is funny in that while the bike was parked out by the SW 9th carts, Portland Pedal Power showed up right next to it. The PPP seem to be having a successful summer and their cargo bikes are a fantastic form of advertising.