It's the calculator that "thinks" only if you think, too -- and now it's available online.

QAMA(TM), or Quick Approximate Mental Arithmetic, is a new kind of calculator designed and developed by Ilan Samson, an "inventor-in-residence" at the University of California, San Diego's California Institute for Telecommunications and Information Technology (Calit2).

Having prototyped and tested a hand-held version of the calculator at UC San Diego and San Diego's High Tech High School, Samson has now launched an online version of the device that allows users to perform any calculation, from simple arithmetic to complex calculations involving scientific functions. But here's the twist: The result is shown only if the user first keys in a reasonable mental estimation of the answer.

The device -- and its inventor -- were recently featured in a story in the Times of London Online, which claims the calculator "head of the Mathematical Association in Britain gushing with excitement." Samson will be gushing with excitement, too, when he finds a manufacturer willing to produce a hand-held version of the calculator on a mass scale.