"Microsoft Calculator Plus has a vastly improved interface over the old version, and even sports a transparency feature that allows you to see through it when it is on the screen but not the active application. If you prefer, you can change the interface to Classic View, so it looks just like the native Windows XP Calculator while maintaining its advanced features.
In addition to the Standard and Scientific views, Calculator Plus provides you with a very comprehensive Conversion view. In fact, there are 11 conversion categories, which include such items as Length, Volume, Weight, and even Currency. (To update the available currency values, pull down the Edit menu, and select the Import ECB Exchange Rates command.) While the layout and operation of the Currency conversion feature may behave erratically, it does work."
VIA:- TechRepublic