View http://javascriptweblog.wordpress.com/2011/01/18/javascripts-arguments-object-and-beyond
I’m not ashamed to admit that the arguments object is something I learned about just now. I’m not sure how unique it is to JavaScript, but essentially you’re automagically given an object containing all of the arguments passed to the current function. That’s just the start though… it’s a pretty quirky thing to play around with, but I can see where it’d have it’s benefits.