I always feel like there's an anti-Tumblr vibe on HN, and I've never understood why. And I seem to recall Marco (one of the lead designers of Tumblr) - making a jab at Paul Graham at some point - though I might be making that latter bit up, since Marco jabs at a lot of people, which is why his blog is such a fun read.
Is there some enmity between the two sets of developers? Is it a Boston-versus-NY thing?
http://www.tumblr.com/goodies
http://www.tumblr.com/vimeo