Oh wow, thank you for this. I've been using tumblr for more than a year, and the only way I knew of getting at the permalink for a post was clicking on the date stamp, which is only sometimes even there. I'd also never heard of Disqus, am checking that out now.

(I seriously cannot imagine a less intuitive and useful social networking platform, sometimes I think everything about it is fundamentally broken. Still, there are pretty pictures, and the tags are fun?)