Wow - that's an early starter. I do know of a few kids who were trained that early but for most kids it's early even when they seem to be ready. Don't be surprised if this is a false start and you end up back in diapers for some period of time. My daughter had me fooled and started - then went back to diapers until she was almost 3. (Darn.)
That being said, I used the Dr. Phil method. I was at work one day when my mom called me and said Dr. Phil is going to have a surefire way to train your kids - so since I work flexible hours I got my butt home to see this. He was trained by the end of the following weekend (it was a 3 day weekend so it gave us 3 days to reinforce it).
1 - make it a positive thing. No scolding.
2 - tell him that if he's ready to use the toilet you're going to have special rewards for him when he uses the toilet. Ask your son what he thinks is a great reward. My son was a huge fan of action heros and he wanted to talk to the fireman guy, Billy Blazes (my husabnd is a police sergeant - THAT didn't impress him at all). So when he used the potty I "called Billy Blazes" (my husband at work - who disguised his voice) to tell him that my son had used the potty. Billy Blazes got on the phone with my son and told him how proud he was, and how cool that was, etc. He was a very exicted boy. I gave him a few M&Ms and told him we'd have a party when we didn't need to use diapers anymore.
3 - the next time he used the toilet we used those little champagne-confetti-popper-things (think New Years Eve) and we all pulled it at the same time (my husband, me, my son and his older sister) cheered (yay for Mark - good going, what a big boy!, etc.) and had cupcakes.
4 - That weekend, when he used the diaper we just changed it and ignored it. We didnt' comment on it, just went about our normal day. When he used the toilet we had a little soda, or a few more M&Ms, we always cheered, congratulated him, maybe had another cupcake.
5 - Each and every time he used the potty over those 3 days we'd remind him that we'd have a special party once we could get rid of the diapers. Again, we said nothing good or bad, when he used the diaper.
By the middle of the day Monday he told us he didn't need diapers anymore. So we had a party that evening. We baked a cake, hung streamers, blew up balloons, had ice cream & soda, invited grandma & grandpa over. We all marveled at him - told him that he's really getting to be a big boy, told him how great, etc. He never used a diaper again.
2 notes: - it was a long weekend when we had nothing planned - no party, soccer game, no trips to the Mall, no distractions. When he felt the urge he could go use the potty. (We did use a small plastic potty that was "right-sized" for him.) Final note - he did have a few mistakes after that - if we were out at the store, over someone's house and he was having a lot of fun. Again, no scolding, no negative comments - just a change of clothes, and while we were changing I'd say something like "I guess you were having so much fun you forgot to use the potty - next time I think you'll remember..." but it was treated like no big deal.
Good luck Mamma - 2 is early but it's not unheard of and it would be great!