If you are a blogger who happens to shoot good photos for you blog (or elsewhere), you can offer them to other bloggers and users as free stock photos to http://www.freerangestock.com. You can associate your adsense account or the site will create a new Adsense account for you. Ads with your contrubutions and profile will give you 80% of all three adblocks that show on those pages. The revenue sharing system has been extensively reviewed and approved by Google, so there should be no credibility questions ;-) Details of the revenue sharing program are here: http://www.freerangestock.com/revenue_sharing.php
Actually, all submissions have to be approved - after upload they are evaluated for their usefulness as stock photography. Submissions must meet submission guidelines (you can read them on the site) -- it's not a personal photo sharing site. You can see on the site what types of photos are accepted. But it seems everyone takes some photos that are good and could be useful.
I don't have a blog but love photography and recently treated myself (ahem my partner lol) to a fairly expensive Nikon digital SLR...this seems like a really good excuse for me to get snapping! Thanks a lot for posting as this really is a great idea... JB