The traffic graphs linked in this post [0] are an interesting addition to the "How often do you visit HN?" poll [1] that was done a week ago. From the graphs, it looks like there are about 10x as many page views as unique IPs.

[0] http://ycombinator.com/images/hntraffic-17jan11.png [1] http://news.ycombinator.com/item?id=2090191