I was about to give in, buy Hand Painter (about $12) and blur/color the drawings with Photoshop. Then I found MoePaint. It's freeware, and it's almost Photoshop for palm. There's an airbrush tool (the paintbrush,) there's layers, so I can color behind my sketching… and it's FREE. So if you're trying to use your os5 palm to sketch, I would definitely suggest Googling this.
Here's a shot from an upcoming episode of my web-comic Webby:
Pretty neat, huh? It's not pixilated like the pictures made with all the other palm-paint programs. I had to add the text with Photoshop, but this is great! I love free stuff.