Google, Yahoo, Bing — and others like them — have useful features that have nothing to do with keyword searching. Like checking a flight time, converting avoirdupois to metric, or doing simple arithmetic. Those tips and others are lists in this article from USA Today. Searching for "Google tricks" turns up a few more lists, like this one: Adding "&imgtype=face" to your Google image search can distinguish Paris Hilton from Paris the city.
