This morning my wife walked into my office with a beautifully ornate wooden name plate, which she placed on top of my bookshelf. This year I turn 42 years old, so 2010 is my yakudoshi, my unlucky "year of calamity" according to a complex Japanese belief system that crossed over from China centuries ago, and my wife had asked a Buddhist temple that her relatives run to say special bad luck-removing prayers for me, writing my name on the wooden talisman. According to this yakudoshi system, the ages of 25, 42 and 61 (for men) and 19, 33 and 37 (for women) are extremely unlucky, and you should avoid doing certain things like building a house, starting a business or otherwise making a major change in your life during these years. (The years before and after each unlucky year are also somewhat unlucky.) Of course, I privately laugh at some of the superstitions the Japanese come up with, like don't whistle at night or you'll be attacked by snakes, or if three people appear in a photograph together, the one in the middle will die young. But the yakudoshi belief is pretty much "the" primary superstition in Japan, held by every Japanese I've met, so just to be on the safe side, I'll avoid building any houses this year.
You can remove bad luck at a Buddhist temple, for a small fee.