The Text tool allows you to paint with words! In the text settings, the first parameter allows you to change the words the text tool spells out as you make your strokes. You then paint in any shape or patterns and watch the words flow along following your finger.
Sometimes you'll want to write some text out in straight lines instead of crazy curves. You can do that too! Just open the Stroke panel and set the shape to Line. Now as you draw straight lines the text will follow along. You'll also find it handy to turn off the text repeat option when doing this.
Check out the Text Compo to see some of the amazing things people have created by painting with text!