SINGULART - World's Leading Online Art Gallery
Drawy - Learn to draw, use camera to score your drawings
DeviantArt muro - DeviantArt muro is an HTML5-powered drawing application that lets you create artworks using the simple touch of your fingertips.
Sketch This - Daily drawing challenges
Artpip - Artistic wallpaper for your desktop, refreshed daily.
Stickman Builder - Free parametric graphic Stickman Builder, creates fascinating stick figures on the fly.