Some time ago I wrote about buzz generating blog advertising site called SnapBomb.
I'm happy to report that they did paid for my review of their site, so I can recommend fellow bloggers to check them out.
Although I'm not pro-spam, this seems very well balanced so it's not annoying.
How it works: if you don't mind some blog marketing, then sign up, validate your blog and wait couple of days. After your blog is verified you will be presented with "opportunities" about which your are invited to write about. Pick those that you really care about and are relevant for your readers. Opportunities are matched to your blog content, so you don't have to fear that you'll turn your blog to a pile of spam. Use your head and don't be greedy and you can collect some change for your domain registrations or other small web expenses.