The Little Packet That Lives on My Bike
I have a small zip lock bag with a copy of my health insurance card, drivers license and credit card and $40. My wife's cell number is on the copy of the health insurance card. Usually I bring all those things with me when I ride, but sometimes I forget. This way I know I always have enough for a snack or drink and information for the emergency room.
My regular riding buddies know about the packet. Sometimes I tell someone in group rides, but not always.