Very interesting that this was posted, as I was just looking at Bobby McFerrin's "Don't Worry Be Happy" and was going to use it to help some students see how the pentatonic scale works. That hit song is nothing but the pentatonic scale.
Talk about an easy way to use of learning how to improvise, do fill in's as you can't play a wrong note.
Also very helpfull in learning any new song as they are the most prominent notes and in many songs the only notes in the melody.
This is probably the main ingredient I use in all playing.
That and a few other simple tricks and you can surpass anything you've done previously musicwise.
http://ScottLMusic.com