Sketch, Draw over image and then Link it

Penolo lets you sketch or draw over someone else’s sketch and then link these art pieces to your Twitter. The service is free but you need to logon to Twitter.There is also the ability to sketch over an image, which you have to just upload from your hard drive or from a URL if you have that handy.You can choose from four types of brushes (based on thickness), use tools to draw a line, rectangle or a circle and ability to insert text.