Blog Neighborhood is a UI metaphor for viewing related blogs.  Today's blogspace is organized mostly by topic (i.e. Java, Flash), relationships (i.e. friends, collegues), or navigation (I am more likely to subscribe to blogs Dave Winer visits because I read Dave's blog).

Blog Neighborhood is a textual representation of blogs a blogger read either by browser or RSS feed.  Essentially, its a vertical list of hyperlinks, each pointing to a blog.  Vertical axis represents time, so blogs I visited most recently are at the top.  Horizontal axis represents frequency of visits limited degradation over time, so hyperlinks to most frequently visited blogs are not indented while rarely visited blogs will be deeply indented.  Axises can be switched.

Here is an example of how Blog Neighborhood looks like:

Scripting News
  Marc Canter
   Lawrence Lessig
Scott Loftesness
   Jeremy Allaire
  Mitch Kapor
    Ray Ozzie
    Don Box

Its primary advantages are intuitiveness (you don't even have to understand it to use it) and compactness (it fits easily in a corner of a blog and simple enough to display on mobile devices).