Google has added a new comparison tool to its search results that allows you to compare two things with a simple search query. Just type the two things you want to compare, and let Google do its thing.
Currently, searches work for nutrition info, celestial objects and a few other things. For example you can search for: "compare butter with olive oil", or make it more complicated with something like "how much saturated fat is in butter versus olive oil".
Fifteen years on -- and we're just getting started [Google Blog]