As I was wrapping up some coursework last night, I cut and pasted a modulus expression into my Google search bar, hoping for some references on how to solve a particular problem. Google instead offered a solution to the problem and pointed me to their calculator function. In addition to the proposed solution, I was offered a link to search for documents containing my search string as well.
This is actually an incredibly handy feature, since any search string entered into Google that looks like a math problem gets solved. This includes units conversions (actually a separate feature), trigonometric functions, logarithms, roots and powers, factorials, and combinatorics. Wow. While it hardly rivals full-featured graphing calculators, it's a useful tool that beats the built-in Windows calculator. Who doesn't have a web browser open all the time? Learn the keyboard shortcuts and this could be yet another reason why I'm happy to sell my soul to Google.