title: Calculate time difference between two dates, and present the answer like "2 days 3 hours ago"
body: <p>Are there any classes/functions written in php publicly available that will take a timestamp, and return the time passed since then in number of days, months, years etc? Basically i want the same function that generates the time-since-posted presented together with each entry on this site (and on digg and loads of other sites).</p>