External aids are things like notebooks, PDAs, lists, alarms and strings around your finger. Some external aids (like notebooks) are intended to remind you of what to remember. These are very effective because your notebook cannot forget. As long as you remember where your notebook is kept, you will always have a backup of information contained in it to refresh your unreliable memory. These types of external aids are particularly useful when you are very busy, easily distracted or don't have time to properly learn the material. In these situations, an external aid acts like temporary storage until you can get the information into your head.
External aids can take other useful forms. For example, you may place the movie rental near the door as a reminder to return it to the store. If you think of something as you are falling asleep, you can put something out of place to
remember it in the morning. You can tie a string around your finger to remind you to do something. These types of aids only remind you that there is something to remember. Usually, this is enough to jog your memory. If you can't remember why a string is around your finger, then you might need to use the first type of external aid.
If having a string around your finger is too annoying, you can try putting other things out of place. You could put a rubber band around your wrist, move a ring to a different finger, put your watch on the other wrist, put your wallet in a different pocket, etc. You can even use multiple simultaneous aids to remember multiple things. For example, your wallet in the wrong pocket could be a reminder to go to the bank and a ring on the wrong finger could be a reminder to pay your bills.
