Oddly enough, mine is the theme from CSI, and some times the Mentos commercial theme.

There's nothing nicer than a tune playing in your head -- until you can't turn it off.

The phenomenon has spanned the ages. In 1882, Mark Twain wrote in a short story of an annoying "jingling rhyme" that became indelibly lodged in the author's mind until he passed the curse along to another hapless victim. This summer, a community board in Brooklyn, N.Y., has called for a limit on the playing of the "Mr. Softee" jingle by ice-cream trucks -- a jingle that can be unbearably memorable for those subjected to it for extended periods.

Research has helped define, but not explain, the experience. A recent study by the University of Cincinnati looked at the affliction, which the author, James Kellaris, calls "earworms" from the German word ohrwurm. The ear part is obvious, but the worm part isn't incidental. Kellaris, a consumer psychologist, says it conveys the parasitic nature of the travel of songs into their listeners' ears, only to then get lodged and played on mental continuum.

He found that some 98 percent of listeners were at one time or another bothered by a tune that wouldn't leave their heads. The study also found some common offenders, including the Kit-Kat jingle ("Gimme a break"), "Who Let the Dogs Out," Queen's "We Will Rock You," the theme to "Mission: Impossible," "YMCA," "Whoomp, There It Is," "The Lion Sleeps Tonight" and "It's a Small World After All."

And, if you've missed it: customs officials are multi-millionaires. Now, who didn't know that?