gistfile1.txt

function urlify(text) {
    var urlRegex = /(https?:\/\/[^\s]+)/g;
    return text.replace(urlRegex, function(url) {
        return '<a href="' + url + '">' + url + '</a>';
    })
    // or
    // return text.replace(urlRegex, '<a href="$1">$1</a>')
}

var text = "Find me at http://www.example.com and also at http://stackoverflow.com";
var html = urlify(text);

// html after:
// "Find me at <a href="http://www.example.com">http://www.example.com</a> and also at <a href="http://stackoverflow.com">http://stackoverflow.com</a>"