Nothing beats pencil, but this app may just convince me to get an iPod Touch:
http://usa.autodesk.com/adsk/servlet/pc/item?siteID=123112&id=13872203
I've used the Mac version of SketchBook Pro and it's very nice.
http://usa.autodesk.com/adsk/servlet/pc/item?siteID=123112&id=13872203
I've used the Mac version of SketchBook Pro and it's very nice.