Screw it - I'll give up one of my easiest things I do. I have a hacked phpbb forum script that does two things.
1 - sends trackbacks and ping notifications and generates rss feeds.
2 - has no registration functionality. Has no way to reply to threads, has no links to profiles, has no way of being spammed or abused by anyone other than me
I install it. Then make about 20 posts for each of my sites over time. I usually reference someone else's blog post so I get the link back in the post.... and one or two of my other sites about every other post.
It's "work" but I don't deal with spam. I don't end up in supplementals, don't get banned, seem to pass human review, etc...
Half the time I'm just referencing someone else's shit and adding a resource box to my sites
.
If I wanted to go a little further I could make a scraper, or markov content. It's just a database so you can do pretty much anything you want. These are part of my foundations though so I do give them more TLC than an auto generated site because I can link from them anytime I want.
I'm sure you could do the same thing for adult sites and even embedd images and video....