In case you missed it, [a man and his wife were recently jailed for three days because they put a note to airport luggage screeners in their suitcases](http://www.sfgate.com/cgi-bin/article.cgi?file=/chronicle/archive/2003/01/14/BA175843.

DTL).  The note made no threats, nor did it make jokes about bombs, hijackings, or other verboten topics in an airport.  After holding the man and his wife for three days, the federal government decided the man had committed no crimes and let him go.  America's airport security apparatus:  defending the unsuspecting public from notes hidden in checked baggage. Last night I decided to examine a chart that details exactly how long it takes someone to get frostbite given temperature and wind speed.  Since my commute is about twenty-eight minutes by bicycle, knowing the weather conditions that lead to frostbite in about thirty minutes is very relevant and useful information.  As it turns out, I've been right on the cusp of entering the thirty minutes to frostbite zone on the chart several times now.  I'm still tinkering with my winter biking apparel, too.  Tonight, I'm going shopping for a really think, wind-proof pair of mittens, a pair of wind-proof pants, and a good thick scarf.  Once I have those, I should be all set to bike in cold weather.