In the era of social networks, it's not clear how to manage your address book. Until now...
Use Your Notes for Tags
...In each contact’s notes field, I put the name of the metropolitan area that they’re close to. That way, when I search for “San Francisco,” contacts in Menlo Park, Redwood City, San Jose, and Black Rock City all pop up, even though I didn’t search for them individually.
This is almost like tagging my contacts with a San Francisco tag. And indeed, I use a contact’s notes field for exactly that. I just type in hashtags like #party for people I want to invite to parties, #gamesday for people I want to come play board games, and #zombiefood for people I don’t want to come play board games. Invite lists are a cinch; I just search for the relevant hashtag.
Print a Hardcopy
Sometimes your smartphone might run out of power. Or get stolen. Or your cell phone company deactivates the line due to a clerical error and simultaneously lock syour phone so you can’t even get to the contacts book. (Yes, really!)
That's why I recommend always printing out your travel contacts on paper, with at least names, email addresses, and phone numbers before you leave on a trip.
Every so often, print your entire contact list on paper. If you don’t know anyone’s contact info by heart—and who does, anymore?—you want a way to find it in case of emergency. When the zombie apocalypse arrives, your next door neighbors will be undead, but your cell phone will be dead-dead. You’ll need to call your friends to come heroically to your rescue. Since your phone is out of power, a paper backup is only sensible. This advice also applies to earthquakes, tsunamis, and One Direction concerts.
Prune Your Book
Since electronic contact lists can grow forever, get in the habit of pruning as you go. When you notice a name you don’t recognize, move it into a contacts folder called “Deletion Candidates.” Then every so often, delete every contact in that folder. And don’t feel guilty about it. They haven’t called you in ages (the meanies!) so there’s no reason you should call them.
Do this a little at a time in your daily browsing of your contacts book. I tried going through my entire 3,600-person contact list at once. It took hours!
Andrew, I hope this helps you tame your address book. To summarize: Use a single address book, merge in data from social networks, and try to limit yourself to one phone number and one email address per contact. Scan your social networks before traveling, take a paper copy on trips, and prune your contacts as you go. Hopefully the chaos won't drive you crazy. And by crazy I mean … zombie apocalypse.