I have had my PDA less then a year
My DS put all the phone numbers in it for me.
I just found the best thing to do was to always have it with me.
If I have it I add things I need to remember to it such as a new phone number, an appointment, a coworks day off, my own days off, any change from my usual schedule.
I also keep all the meds I am on in it since I am on a lot and whne asked in an emergency I almost always for get something, I also keep my allergies there too.
I am in grad school and I recently found a great program for school thru school and the best thing it is free, it is a pharmacy program ( I am a nurse).
I even put reminders in there for myself so I do not forget to do things.
Don't forget those important things like appointments, wether they are for me the cat my son or my hair I need to remember them to get to them.
I try to look either before bed or first thing in the morning at my calander so I do not forget anything.
Agaian, it doesn't help unless you have it with you...it makes the task less daunting to add one appointment then to have to add 10.
Also learning to use the graffitti was the greatest time saver also.
Ruth

Ps lets not forget the games....