Shutterstock and Dreamstime allow you to sell images on an editorial license, meaning that purchasers will only be able to use the images in editorial formats (e.g. magazines, newspapers, etc). This is useful for images that you have taken which are of specific interest (famous people, places, current events...) and may not have model or property releases.

This sample editorial image from my collection was taken on the day of George W. Bush's inauguration and depicts items that might not normally have passed as royalty-free for various reasons. It is usable as editorial imagery because of the public nature of the event and the public interest in the event.

Dreamstime offers an editorial license in addition to their other licenses:

Shutterstock has a program to help photographers get access to special events. (The only catch is that the photos need to be exclusive to Shutterstock for a time). See below for more details.