Originally Posted by JD

nevermind my earlier post

Cms: http://bo.cheapestwebsoftware.com/
Links: http://lo.cheapestwebsoftware.com/
Ads: A series of mirrored domains with a master domain running openx

But since you said Wordpress... you might be able to hack up wp MU... or make a master blog (use a blank theme so there's no html to be spidered) with categories for each niche/site/etc. Take the rss feed from that category and feed it into the satellite blog(s).