My secretary/receptionist uses the HP Connectivity Pack software on the office PC to help me maintain an up-to-date schedule. I enter changes in my 95LX's Appointment Book as the day progresses and set aside specific times for my personal activities.
Since my secretary has a copy of my APPT schedule file on the office PC, she can update it at any time as people call the office to schedule appointments with me. At the end of day she downloads my APPT file to her desktop computer, merges her schedule with mine, and consults me as necessary to resolve any time conflicts.
I then upload a copy of the reconciled schedule.
This procedure lets me keep a running record of all my activities for future planning purposes, and ensures that I am aware of all appointments scheduled for me. It works so well, I've thrown away our old paper appointment book (with all of its erasures and illegible scribbles).
I also use the prioritized to-do list function of APPT to make sure I no longer forget little details that pop up throughout the day.