alarm clock instead, and lord knows we've seen plenty, from tickers that chomp your change to clocks that give you target practice. What we don't see that often is a clock that makes you think at the same time it provokes a physical action. Thus, the Twist Alarm Clock, which displays a simple math equation when it's time to wake up, but requires effort to silence. In order to quiet the alarm, you have to twist the numbered dials on either side of its LCD screen into the right position -- in this case, to figure out what minus what equals two. It's no Turing Alarm Clock, to be sure, but this human number cruncher's actually for sale; you can get yours for ¥2,625 (about $28) in Japan.