What's a good age for a baby to give up the pacifier??

My son is 14 months old and still uses a paci. He mainly only needs it durring naps, bed time and when we go for a drive. A friend saw him sucking on it the other day and asked with a shocked expression if he's still using it, and her baby is like 5 months younger than my son. He also still has a bottle that he uses at nap,bed, and drive. Any body have any ideas for me? When did your kids let go of their paci???