Here's what it appears to do:
1. A referrer information is gathered on each page hit via javascript and submitted to his server
2. The Analytics page uses Ajax to grab the aggregated data, then charts it using the Google Charts API
That's it. At first I was really interested in it because its beautiful, but on a second look it doesn't do anything that Google Analytics doesn't already do except easily show you referrals from a set of sites that you care about.
The graphs get a bit pointless after a day or two, though. If people are interested in playing around with analytk then maybe I'll open it up to URLs from elsewhere and work down some of my 'to do' features, like 'show me just the day/week'.
Thanks for the beauty vote, I wrote it to look great on my iPhone :-)