Facebook Vanity URLs

Hi all,

I've been wondering this for a while now about how Twitter/Myspace and now Facebook creates what they are calling "Vanity URLs"

So, their users use their username as their url.

ex. www.mydomain.com/myusername  would route to their user profile.

So my question is, how can you accomplish this with Zend Framework AND still have other controller/action pairs as well?

Is there a way to setup a custom route where you check to see if that first param in the URL is a username, then if not.. attempt to use default routing?

I have been using default routing completely in the site I am building so I am very new to the router.

Thanks in advance for your help!