Potty Training Update

In case y'all were wondering, today was day 3 of potty training and we had NO accidents.  Yea for Sam!  Notice all the big stickers on the poster...not only is he sitting on the potty but he's actually "doing" something when he sits.  I really think he's  getting the idea.  He still gets really excited ; it's sad to think that will wear off soon.  So my question is "When do we start going out in public with just underwear?"  I guess we'll know when he's ready for that...