Italian sodas can be a sophisticated thirst quencher or a hit with kids at a picnic -- a treat they can make themselves.
Put ice in a tall drink cup.
Add about an inch of the flavoring syrup of your choice.
Pour in fizzy water to about an inch from the top of the cup.
Optionally, add half and half.
Add a straw. The straw is both for mixing and for drinking the soda.
Kids in my neighborhood love making the sodas themselves and showing their friends how to make them.
The syrup bottles are made of glass; if your event is outdoors and kids are involved, it works well to have a bucket or something that they can put the bottles in to avoid spills and breaks.
This is a great potluck contribution for those of us who don't cook.