whos.amung.us: I love these alternative domain names. But even better than that, I like this application that tracks recent visitors to your blog or website and displays them on a simple graphic on your page. Installation is dead simple and the information is quick and current. You visit the link above, copy the code on the main page, paste it in your footer (or anywhere else on your template that gets loaded with every visit) and you are all set. Now if you click on the graphic that is generated, it tell you recent unique visitors to your pages, the list of pages being visited and updates the list in real time. There is also a Firefox Plugin for quick stats checking. Additionally, there is also a popular pages heat map of sorts. I have implemented it on this blog for the time being and you can find it at the bottom of the blog in the footer. As is customary for me, I worry about the financial model and the longevity of this sort of a tool.
[EDIT] This sort of a feature existed with ReInvigorate and I was really hoping that they brought it back. But since I have been beta testing it, it has not been on there and I really miss it.