Ya know, I trained all three of my kids in one day. I know it is hard to believe but never did I have to use the pull ups or training pants. A huge part of the training though was them being able to completely manage the process themselves so we did not graduate to the small potty seat on the big toilet until they were big enough to get up there themselves.
With my first I started with a book called "Potty Training in a Day". I followed it to the letter and it worked like a charm. He was potty trained by noon that day and NEVER had an accident, even at night. For the second one I used some of the techniques in the book but modified it quite a bit to suit his personality. He really responded well to bribery and added a treat/toy bowl to the mix. He was potty trained by 2pm on the first day, NEVER an accident. With the third, I followed the book a bit closer than the second one but still introduced some bribery since she is quite stubborn. Believe it or not, the two boys trained faster than my girl, she took a full day.
Three key components though are; have them do it themselves and make the decisions themselves, be sure to wait to train for when they no longer wet their pants at night, and last be sure they are at the stage where they are not in the so-called "Terrible Twos", when they are in this stage they are so defiant and it will not work. I waited until they would listen readily and understood the concept of what was going on. Starting too early just causes problems.
Probably more than you wanted to know but hope it helps.
Good luck.