One of the cool features of Yahoo! Messenger is "IMVironments™ -- or simply "IMVs". IMVs are kind of like a skin for your IM conversation window, but can also include interactivity and links to more content on the web. (See the full list of IMVs.)
Today I was playing around with the Spider-Man 2 IMV and noticed a link to the official Spider-Man 2 blog which includes a "how to blog" section, templates for Blogger and LiveJournal, and a "production web log". The latter is kind of spotty and the RSS feed is out of date compared to the live content, but overall this is quite interesting.