What is that singing technique called when u...?

go through a series of notes really fast, sorta like what usher does a
lot.
For example: 1:06 in
http://www.youtube.com/watch?v=SOI4OF7iIr4feature=autoplaylist=PLAC07B8901FBF585Aindex=105playnext=1

when he sings the word "everyday".
I hear a lot of good singers do this, and it might be some sort of
variation of the vibrato, but i wanna learn how to do it?