The moment I saw this thread I thought of Jason Mraz and I'm glad someone else posted him! On his CD "live at java joes" he scats at least 40% of each song and it's so much fun.
I vaguely remember Jill Scott and someone else singing "Summertime" on that Bravo Special "Broadway's Best" and doing some scatting...maybe I'm just crazy.
"Who says you can't bend over backwards and eat bugs if you want to? I guess the bugs would probably say you can't do that that, but assuming that they are willing and consenting bugs, then there's no problem. Let's wig out eating bugs."
-RuPaul