My DS is 2 and a half and can drink out of a regular cup but demands the sippy cup. I think he likes the fact that he can walk around with the sippy and not have to be careful. Maybe he also likes the sucking motion, I dont know. Should I be trying to break him of this habit or does it not really matter?

I had my kids use a cup at the table as soon as they were able but a sippy cup when we were out or I was worried about spills. I switched to a straw cup pretty quickly I think.

I would try a cup with a cool straw. That would probably kick the habit fast. Many cups have lids with a hole in it for the straw.

the guy who invented the sippy cup is my hero and i will use sippy cups until my children are married and moved out of my house if i can get away with it! i love the convenience of being able to throw a sippy cup into the diaper bag and run to the store without worrying about spilling. i love being able to hand my four year old and my two year old their sippy cups and let them run around the house without worrying about spilling. we use regular cups with both girls at the table and they do fine with them, but for everyday use and when we're out, we use sippy cups. i don't think there really is a "cut off" for young children.... maybe kindergarten??? or first grade??? or college graduation..... :)