Every now and then I look at the "Be a Guide" link at the bottom of this page. Right now there's an opening for someone to create an About.com site dedicated to dinosaurs, and I am all for this. Dinosaurs are an odd subject, wildly popular but to me they're just another group of fossils. I have a source list for dinosaurs, but I write very little about them myself. So, by all means join up and take over the subject!
I also like to read the list of openings and daydreamfor instance, there's also an opening for an About.com Guide to Cheese.