Start decorating with five-leaf clovers. See if anyone notices.

Really? I didn't know that.

For the clue-deficient:
http://en.wikipedia.org/wiki/Four_leaf_clover
http://en.wikipedia.org/wiki/Shamrock

You expect them to be able to count to four?

And of course, you know the story of the very lazy baker who wanted to slice as many pieces of bread as possible with one swipe of the knife, but had difficulty finding bread knives that would cut multiple loaves. He had no trouble finding a knife that would cut two, and eventually found a nice long knife that would cut three, but he had to search and search, and talk to all kinds of smiths and ironworkers in the hopes of getting one that would cut four. Finally, one day he came home to his wife and announced, "Today is my lucky day. I just found a four-loaf cleaver."

Nate

Back when I lived in Baltimore, a local seafood restaurant ran an ad in the local free paper for their lobster special, and three of the four corners of the ad contained clip-art photos of lobsters. The fourth corner had a clip-art photo of a scorpion.

Small differences matter.

But a 4 leaf shamrock ... now that would be REALLY lucky.