Automattic Stats plugin for WordPress...
Blogs hosted on WordPress.com have a nice statistics module that integrates into the dashboard. Yesterday, the folks at Automattic released this as a standalone plugin for self-hosted WordPress blogs. The developer, Andy Skelton, has more info.
Installing the plugin is really easy - copy the file into the plugins directory, activate it through the dashboard, and enter your WordPress.com API key - a process almost identical to installing Akismet, the excellent comment and trackback spam filtering plugin.
The dashboard page includes most of the statistics that bloggers would be interested in - referrers, top posts, search engine terms, outbound clicks, and incoming links, all laid out in a clean and easy to read format.
I installed the plugin yesterday and I'm liking it so far. It hasn't slowed down page loading times at all, and the statistics collected are useful and relevant. I'm using it alongside FeedBurner's StandardStats feature, which I've been using for several months and have been pretty happy with. And, of course, I also use AWStats, which ASO enables on all their packages by default. What can I say? I like numbers and pretty graphs. :)