SwarmSketch is an ongoing online canvas

http://swarmsketch.com/

Crayola Digi Color

http://www.crayola.com/coloring_application/index.cfm?referrer=/coloringCraft/craft/index.cfm&mt=digicolor

Make Believe Comic Strip
http://www.makebeliefscomix.com/
Make a comic strip online

Art Studio Chalkboard
http://studiochalkboard.evansville.edu/
Art Studio Chalkboard
These pages are a resource for artists and art students that focus on the technical fundamentals of perspective, shading, color and painting.
They were compiled and designed by Ralph Larmann, art faculty member in the University of Evansville Art Department, and are intended for educational use only.
Sketchplanet
http://www.sketchplanet.com/
Sketchplanet is an online user-driven sketching community.
AllMyMagic
http://www.allmymagic.com/wizcard/create
WizCard is an online drawing tool that allows you to draw, paint, upload image, use provided graphics and even add music to your one-of-a-kind WizCards.
You can then send WizCards to friends or post them in your blog or any social network.
DrawAnywhere
http://drawanywhere.com/
DrawAnywhere is an online diagramming website, where you can draw, modify and share flowcharts and other diagrams, with the look & feel of a desktop application.
It runs on any browser with Flash 9 installed. There is no need to download and install any custom software. It runs entirely on the web, and thus it is an always-on-access-anywhere solution.
It meets all your diagramming needs without installing, maintaining and purchasing expensive software.