How to say no?

Stacia
With the holidays coming up we will be attending a lot of family functions. This Sunday (11/8) we will be going to a Thanksgiving dinner/family reunion. I'm a first  time mom and our son (7 weeks) will be the only baby there so I'm sure he'll be getting a lot of attention. I don't want him to be passed around as that happened at Halloween and he became very overwhelmed/overstimulated and anxious. Do any of you have any suggestions on a nice way to say "no, you can't hold my baby"? I don't want to come across as rude, but I don't want him passed around like a hot potato either!