The balloon ball fabric balloon covers are meant to address this. They have a button-hole-sized hole into which you insert balloon and blow it up. You are right...balloons are a choking hazard and I personally hate them (I am afraid of the popping) so it's funny that I'm even thinking of the balloon ball covers as party favors
Please keep the ideas coming! These are great ideas (love the egg shakers and the snack trap ideas!) and I can see using them for the next couple of years too!