Excellent that your son is very clearly exhibiting his awareness of his bodily/elimination sensations! He is learning how to coordinate the feeling of having to go with getting to the right place to do it, and then once he's there, engaging the correct set of muscles to get the pee out, etc.
If you really want to help him make the connections much more quickly and effectively, and without giving him the mixed message of diapers, go buy or borrow some simple, non-waterproof, cotton training pants (Gerber cotton training pants are available at Target or WalMart!) and switch to those. Yes, you may have some accidents to clean up, but trust me, it won't be for long! Don't waste your money on the pull ups or feel and learns - they'll never do the job of the training pants in terms of helping him figure out how to use the bathroom. They send a mixed message to your son and they're ALL glorified diapers even though the companies say "training pants" and charge you an arm and a leg for them.
The best ways to help him are to work as a close team together:
* have little potties readily available around your house
* maybe even keep a little potty in the car as well and offer upon arriving and leaving when you're out and about -- OR offer regular and frequent potty breaks at the store while out and about (make it your routine to hit the bathroom first thing upon arrival someplace, for example)
* be aware of his "gotta go" signals and say "lets go read a book on the potty" when you see those signals - like if he's dancing around holding his crotch, or farting, or getting antsy/wanting to get out of his chair towards the middle or end of a meal (big indicator that he likely needs to poop), and upon every waking (first thing in the morning, right after a nap, etc.)
Great resources & books that I've used for potty training:
Dr. Sears on Toilet Training
http://www.askdrsears.com/html/10/t106600.asp
Indicators That Your Baby/Child Needs To Potty:
http://www.diaperfreebaby.org/index.php?module=article&am...
Diaper Free Before 3 (by Jill Lekovic)
http://www.diaperfreebefore3.com/
No Cry Potty Training Solution (by Elizabeth Pantley)
http://www.pantley.com/elizabeth/books/0071476903.php
Those are a good start - just stay consistent (pee/poop goes in the potty as opposed to "oh, go in your diaper now, but not later"), communicate with him about his elimination in a stress-free, non-judgemental, supportive way no matter what (whether it's an accident or in the potty), and most importantly, enjoy it. It really is fun! Happy pottying!