String.prototype.parseURL = function() {
    return this.replace(/[A-Za-z]+:\/\/[A-Za-z0-9-_]+\.[A-Za-z0-9-_:%&\?\/.=]+/, function(url) {
        return url.link(url);
    });
};

String.prototype.parseUsername = function() {
    return this.replace(/[@]+[A-Za-z0-9-_]+/, function(u) {
        var username = u.replace("@", "")
        return u.link("http://twitter.com/" + username);
    });
};

String.prototype.parseHashtag = function() {
    return this.replace(/[#]+[A-Za-z0-9-_]+/, function(t) {
        var tag = t.replace("#", "%23")
        return t.link("http://search.twitter.com/search?q=" + tag);
    });
};