Dance cards today.
Wikipedia explains that these little mementos are "used by a woman to record the names of the gentlemen with whom she intends to dance each successive dance at a formal ball... In modern times the expression "dance card" is often used metaphorically, as when someone says 'pencil me into your dance card,' meaning 'find some time to spend with me.' Conversely, someone's 'dance card is full' implies that even though they may be interested, they have no time."
Pierre Aldebert Griot, Berlin 1750-1760
Museum of Decorative Arts Berlin
Société Philharmonique Dance Card
Conversation about the Dance Card preparations for a ball 1882
by Carl Hermann Kuechler
Designed as a miniature lady's purse having attached order-of-the-dance booklet with gilt lettering and attached pencil
Dance card for celebration of the Society for Art and Science in 1883
by Paul Düyffcke
Dance Card, Her Majesty Queen of the Year, 1916
Newport Dance Cards
photo by Peter Lee
* A Pinterest board of turn-of-the-century dance cards
* Another Pinterest dance card board
* Some dance card info
* Haven't seen the movie, but this ball looks like dance cards would have fit right in.
* Dance cards would work at this Stanford ball too.