Online maps

Does anyone use an online mapping system that allows you to share annotated maps?
Example: I'm on a trip and mark my stops along the way, then someone in my "friends list" could look at my marked up map and add some more points of interest, etc.

Just curious if there is something out there.

Something like this? I have seen some fascinating personal maps on this site.

http://platial.com

That has the right idea. But it seems to lack a lot of "street level" images.

Maybe that's my problem, I can't find a service that offers platial's social-sharing with great street level maps.

Thanks for that link, I already found a bunch of bookstore related maps on there.