I have my calendar at work synced with my phone. I have reminders on there for EVERYTHING. Birthdays are automatically recurring, dentist, doctor, meetings, holidays, vacations, kids practices, games - everything. My ex used to laugh at me b/c my phone reminder would even go off to pick up the kids from something (church, practice, etc.) that how could I forget about them? It's not that I would forget (ok, maybe its possible), but then I know I have 15 minutes to finish up or get ready to get them.
It is truly my lifeline and I would be completely lost without it!