Can i switch phone models if i stick with the same company?

my family and i share a two-year family plan contract with cingular. i have had my phone for about a year now, and it was really expensive. however, i would really like to change phones, but i'm stuck for another year. how much would it cost to break contract with them and purchase another phone even if i still have cingular as my carrier?Can i switch phone models if i stick with the same company?
Yes you can purchase a new phone at any time. But depending on your contract you may be eligible for an upgrade where you get a discount. And if you have a new phone and you have had it less than 30 days.. most companies will let you come in and try a different one if you do not like the one you have.