SumoPaint - http://www.sumopaint.com/web/
In Sumo.Fm you can find inspiration, remix and create images with friends. Tune photos, create drawings or just fool around with images. In Sumo.Fm anybody can create - whether little inspiration or a work of art - and then publish it for friends or for the world to see.
Flickr - http://www.flickr.com
Flickr is home to over five billion of the world’s photos. Get a glimpse of another world by diving into the official White House photostream or the newest images from NASA. Or explore a moment in history with archived collections from the Smithsonian, Library of Congress and more in The Commons. See the world through someone else’s eyes, right here on Flickr.
Picasa - www.picasa.google.com
Google's Picasa software lets you organize, edit, and upload your photos in quick, easy steps. It provides 1GB of free storage that makes sharing photos a snap. Picasa allows you to share your pictures directly to Google + without any hassle.
Posterous - http://posterous.com/
Posterous is a social platform that is powerful and easy to use. Use Posterous in your classroom to stay in touch beyond the classroom, easily publish class materials and multimedia, privately share class updates and ideas, and blogs about course content. You can publish through multiple places using web, via phone or any other devices in a safe way. You can link your Posterous to your Twitter and Facebook accounts as well.