Lists, post it notes, white board, and calendars on the fridge for remembering dates and appointments and events.
For remembering where everyday necessary items are located. Put a bowl or basket on a table or shelf (that you can hang just for this purpose) near the door that you use to go out of the house. This is good for keys, cell phone, glasses, and sunglasses. Always put those items right back into the basket when you get back home, so that they’re always in the same place.
For things that you need to do after work. Put a post it note on your dashboard or passenger’s seat (if no one is sitting there).
For odd items that you need to take with you to work or to the gym (or wherever else you might be going) that are not every day items, put those items on the floor or in a basket right in front of the door that you use to leave the house in the morning, but put them there the night before.
If you are supposed to be bringing something to your company potluck, leave your cooler on the kitchen counter (right next to the coffee cup you will use in the morning) so you won’t forget to take the salad/casserole/cheeseplatter/chili with you in the morning. Even if you open the fridge in the morning, to get the cream, unless you have a note or a big fat cooler sitting there in plain sight, you will not see the giant lasagna that you wife made the night before, because you’ll be too bleary eyed.
If someone invites you to an event (like a baby shower or a play or a ballgame) tell them to please phone you about 2 or 3 days before the event, again, so that you will not forget. Do this in addition to marking it on your calendar (even though your calendar might be currently on August, but the event is in September so you might not be looking at it).
If you are clacking away on Fluther, but you are supposed to leave to meet someone for dinner, take the wet clothes out of the washer in the garage, mow the lawn before it gets dark, put the meat in the crockpot 6 hours before your wife gets home, set a timer. The best ones are the old fashioned portable wind up ones (rather than the electronic ones on your stove or microwave) simply because they are portable, and only give you 60 minutes before they ring. Put it next to your computer. It will startle you back into reality very quickly.
I don’t have a Smart Phone, but apparently you can set up alarms for all sorts of things, so if you are at work and need to do certain tasks at certain times, you can set up your phone to alert you.