Share My Map lets you create a map — and a “social community” of others who can contribute to it by adding points of interest, photos, video, or text information.
After registering, it’s pretty easy to use, and you can embed Flickr photos just by using their url address. People can comment on the map but, there again, you have to register first (it’s pretty easy to do so).
A group of students could use this site to create a joint project describing locations on a field trip, or to describe and show a historical group of explorers.
I’m adding the link to The Best Map-Making Sites On The Web.
I’m also adding it to The Best Online Tools For Collaboration — NOT In Real Time.
Thanks to Google Maps Mania for the tip.