Corrected entry: From various dates, ages, and bits of information given, we know that, at least in the first episode, everyone (everyone being Clark, Chloe, Lana, Pete, etc) is 15 years old. Do the producers really expect us to believe that they're 15 years old? Clark's played by a 24 year old for one...
Phoebe
28th Oct 2003
Correction: Yes. This practice is used all the time, and people are often surprised to find out that their favorite actors are older than they thought.