I think carrying around dongles is a hassle (I know some people are very organised with their peripherals, but I'm not one of them). I like the idea of the docking stations some people have posted about, but it doesn't really account for needing the ports when you're away from your desk. It's not often, but I do find myself needing them now and then.
It's not truly portable, but it's a nice setup for having a desk and carrying your laptop with you to meetings and home.