OS X: Spotlight is your quick calculator
Every day I find something new in OS X which makes me wonder, why this could not have done in any operating system. Every OS has nowadays a full-index search. Microsoft’s Vista-search just sucks, as I have never been able to index everything properly, Google Desktop is better, but is very intrusive and CPU-intensive.
OS X Leopard’s Spotlight search functionality seamlessly integrates in the menu-bar. You quickly activate it via CMD+Space and search results are produced as you type. It will categorise the search results (and will even show you the dictionary definition):
Spotlight also functions as a basic calculator and spits out the answer as you type it in and supports: * is multiplication, / is division, ^ is to the power of (exponents), ! is factorial, and then of course there’s + and – for addition and subtraction, respectively: