While I’m definitely a fan of the uber-simplistic and sexy approach to blogging by tumblr, there clearly exist some basic functionalities that are missing and tumblr has been late to add. And, as I haven’t been serious enough to create a personal website including a WordPress /blog yet, I’ve just added commenting using disqus and ajaxed search using this hack. So, all your comments are welcome by now (to the older posts, too!) :)
P.S: What about trackback? Any roundabouts?