There's a Facebook page where you can sign up for. I'm about to buy a single-cup coffee maker just so I can use all these k-cup freebies. Plus my current method of obtaining coffee is a tad troublesome. I've almost been caught twice in the last week alone sneaking through my neighbor's kitchen window.
The site has been spitting out errors all morning, so you might have to keep at it for a while. You should eventually see a cartoon image of a girl sitting in a room. Leave that page on your screen for a few minutes and then a form should also appear.