One of the very coolest utilities around for bloggers is the TouchGraph Google Browser. This handy thing will give you a visualization of your "neighborhood" --that is, a map of sites Google considers similar to your site. A node is created that connects to other nodes that connect to, well, you get the idea. It's easier to draw a picture than to explain:
Blogger Forum's neighborhood
Although you probably can't read it, the yellow center in the picture above represents the Blogger Forum site. All the surrounding nodes are similar sites and links to their own similar sites. One of the cool things about this is that you can click on any site's tab and get a description of the site and a link to the site. You can also drag nodes around to get different perspectives. It allows you to see at a glance the relationship between large groups of URLs, helps you find other sites within possible interest groups, and give you some insight into how Google views your site. You can also use it to make interesting searches where you want to find areas and relationships rather than the usual Google listing of sites. Thanks to Google Hacks.