Remember in The Sound of Music when Captain Von Trapp used a whistle to summon his children. Each child had a specific call. We have a similar arrangement in our house, albeit unintentional.
I've had a congestion cold for a long time, almost a long as I've been pregnant. I go through boxes of tissues, my face is always red from blowing my nose, and I never leave home without a stack of tissues that dwindle to nothing by the end of the trip.
Now, whenever I sneak away for awhile, whether it be a bath at night and leave Luke with Mark for some solace time, or time alone in the office to pay bills or wrap gifts, my family immediately knows when I've returned to join them. It's pretty sad when across the house the sound of a nose blowing is the signal that mom has returned. From three floors down Luke will hear me, yell "Mommy!" while both Mark and I laugh at the sad reality that Kleenex and stuffy noses are now associated with dear little mommy.
Of course, there are worse functions to be associated with, so I should be thankful ;)