Quoting Click Me Click Me!!!:" There's nothing u can really do my son was interested in the potty thank god because 2 in diapers is not what i wanted lol. My son will be 3 in december."
LOL. I had both kids in diapers...same size too! That was fun.
But there's nothing you really can do. You can't force them to do something that they don't want to do. I tried PTing my DS since about 18 months on (but would stop when he's clearly not having it) and he's now 3 1/2 and is finally fully PT since Aug or so of this year on. Some kids take their time. And that's ok.
You can buy books and such about potty training (like Elmo's potty book) and such and talk about the potty and have him sit there.