The Official Google Blog mentioned that they are bringing one of their features out of the shadows in order to help searchers find sites that are related to those in the search result. According to the post, Google has actually:

offered a “Similar” feature on results for a while now as a way to discover new, useful sites, but it hasn’t been too visible. Since we’ve been continuously improving this feature and we think it’s really useful, we’re now going to start showing these alternative sites more prominently. Starting this week, for queries where similar sites are likely to be helpful, we’ll display a list of “Pages similar” at the bottom of the results page.

So when you do a search now, some of your results will now have a “Similar” link next to the handy “Cached” link.

The current search is then re-ran and sites with similar content are supposed to appear.  I tested it out briefly this morning and liked what I saw.
For those of us “advanced” searchers, we can manipulate what Google’s doing here to help in other ways.  Say for example that you want to find sites that are “Similar” to 3 Geeks…  simply type in this search:

The resulting search will show you other blogs that have similar content to us. This type of searching can be helpful for Competitive Intelligence Analysts that find unique websites and want to see others that are like it… or are looking for competitors of a certain company.  For example, if I type in ““, I get a listing of other BigLaw firms.  If I type in ““, I get a list of legal research websites… and so on, and so on.
This is a pretty useful option that Google is giving a second chance. If you’re wanting to find your website’s relations, then the “related:” option from Google is something you’ll want to test out.