Here’s a set of Dateless Mini-Site WordPress Themes. There’s not just 1, not just 2, but 7 different themes that use a very stripped down basic theme that’s perfect for niche mini-site blogs.
Boring Memo is a WordPress theme designed specifically for search marketing. Its very plain and dull appearance makes the advertising on the pages the star of the show.
Here’s some info on a plugin from Dagon Design that allows you to easily recycle posts on your niche blog.
A fix to the Top Commentator WordPress plugin to prevent it from being hijacked.