Down at a pub this last weekend, and there was this blues/R&B combo with a guy scatting on piano. Most folks sing, rather than hum the notes. Regardless, it's a cool sound. You hardly ever hear people doing this (outside of George Benson, mentioned in a previous post), and done properly, it turns heads in a major way. Like a wah pedal though, it's pretty easy to overdo that sort of thing. Remarkably effective if your ear is sufficiently trained (unlike mine) to scat a harmony line with a guitar lead.

As the Blue Raja said: "Keep up the good work...the GOOD work".