I have used Technorati in the past, mostly to claim my blog and check on specifically tagged blogs (such as the ones for the conference I attended last week - most tagged with xml2006), but I've never played with the "popular" books, movies and news features. I can see those being *really* helpful when trying to find a new book to read or movie to watch. Sort of a meta-review collection from real people, rather than professional reviewers. I think that is a pretty cool application of Technorati's technology! "The Prestige" was one of the popular movies listed when I visited, and I thought that the ability to scan through the blog posts and get people's opinions was helpful - I'd seen the movie already, but if I hadn't, I definitely would have found the almost universal approval of the movie very helpful in making my decision!
I also added a couple of blogs to my favorites list (something I'd never done before) and was having fun looking at all of the cool things I can do with my favorite blogs! I'm definitely coming back to this when I have more time!