Stut-t-t-er effect

["Veda, Qua" <qua.veda@intel.com>]

Title: Stut-t-t-er effect

Hi,
I don't want to bother Rick at this time with this question.
On this audio clips, he has some great vocal grooves going.  I'm curious what devices are used to create the 'stutter' in the sounds that give them a percussive, rhythmic quality.   Very inspiring work.    Anyone know what h/w or s/w will create this effect ?  

Also,  I may want to try some vocal looping - quasi beat boxing -  to see what happens.  What mics are recommended for this application ?

Thanks!
-Qua