I am always searching my purse and pockets for the appointment cards that we get on the way out of my kids' pediatrician appointments. When shots are involved my only goal is to get out the door. So it isn't until days, weeks or even months later that I remember the small paper reminder the receptionist handed to me as my wee one wailed or flailed in my arms.
To keep tabs of my children's appointments as well as my own, I use the camera on my BlackBerry to take a snap shot of the card and its important information. Then when I have time later, I type the details into my calendar so it sends me a reminder. This trick also comes in handy for dry cleaning tickets.