12 days in- my experience so far. (Long!)
I like reading about how it's going for others for encouragement so I thought I'd share.
We began prepping him about the potty by putting his BMs in the toilet and having him flush it a while ago. We got a few books (Potty Book for Boys and Diapers Aren't Forever) and read those at bedtime. Two weeks before we were going to start we started putting him in pull-ups and told them they were his "trying diapers" and that he could try going on the potty whenever he wanted. Then a week before I took him to the store to show him the underwear he'd be able to pick out all by himself when he was big enough to use the potty all the time. That excited him b/c he saw Diego and Toy Story underwear. All week he'd ask to sit and then ask if it was time to go to the store to get his big boy undies 
The only official method we used was to ditch the diapers during the day and commit. At this point he was waking up dry more often than not, asking to be changed after he pooped, and peeing on the potty if I'd prompt him. So we felt his was physically ready to start.
When we were ready to start, I took him to the store and let him pick out his undies.
Day 1- We prompted him to try. He got a sticker for just sitting and a gummy bear for going. He had one poop and one pee accident. We sat him on the potty after each accident and told him flatly poo and pee goes in the potty.
Day 2- We reminded him to tell us when to go (all the time!). Same reward system. Again one pee and one poop accident. Same approach.
Day 3- This time we told him he'd continue to get a sticker for trying and that he'd get a gummy bear if he initiated and actually went. Again with the one poop and one pee accident. Grrr. Still trying to be matter-of-fact about the accidents.
Day 4- went to camp so I was nervous but he used the potty there and stayed dry ALL DAY! Woohoo! He was very proud of himself. I had bought him the Dora backpack &map since he loooves Dora. I put it in the mailbox and had him get it. I told him Dora sent it b/c she was so proud of him.
Fast Foward to today, Day 12. He still has random accidents (just pee- no more than 1 a day) usually when he is too busy playing or when he's very tired and being stubborn. He's had 3 days of no accidents. Since we started, he has stayed dry during all sleep as well but we still let him sleep in pull-ups or training pants just in case. We keep him in underwear all day- even on outings, reminding ourselves that accidents are part of the process. He's yet to have an accident outside the house! He gets pretty upset when he has an accident. He often tells us when he has to go but I still remind him to go a lot and I think it will continue like that for a long time b/c he's a very active 2 1/2 year old.
I just wanted to share b/c it may be taking a couple of weeks but he's making progress and we celebrate that everyday with him. For us the key was knowing he was ready and taking the accidents in strides even though it's so hard to do.
Hope this encourages someone!
Re: 12 days in- my experience so far. (Long!)