We love calculators that click. While the iPhone's calculator app might do in a pinch, some actions still benefit from physical feedback. The 10 Key Calculator, by the Japanese design studio Takumi, has a snappy response that makes crunching numbers a cinch. It also comes equipped with a USB cable, for those laptop users who hate doing addition with the top row. 

A timeless design that will class up any desktop, we dare say it might be the last calculator you'll ever buy.