Oh, this is so much fun. artPad is a basic, free on-line tool provided by art.com. When you first access the site, you can watch a series of strokes, as it replays the steps in creating a particular masterpiece. It even has controls to speed up the animation, jump to the end or to the beginning. There are some amazing pieces to view. You can add to this painting, or choose to create your own.
You have a paintbrush, paint bucket, and text tool at your disposal. You can choose the color and opacity, and set the paintbrush size. Once your work is complete, you can select a frame and view it in the gallery of your choice: vintage, sports, modern or fantasy. Clicking the save and send button will assign a webpage address to your masterpiece and allow you to send the link to someone via email.
I think this site would be especially fun to use on a SMART Board.