The Formal Kit
The kit that goes in the breast pocket of my tux behind my pocket square. It's for all those little emergencies that happen at formal affairs (dress straps breaking, hair not staying in place, etc.). It was assembled predominantely for the use of the ladies in attendance.
One regular band-aid
two spot band-aids
Needle wrapped in thread.
Also, gentlemen, it should be standard operating procedure to offer up one of your external coat pockets for use by your companion. Formal dresses don't have pockets. Personally, I recomend the (your) right side, as that is often the side she will be standing on.