A few apps that can Help you keep track of friend info, in the moment or for later.
A birthday manager that syncs with the cloud and keeps track and notifies of birthdays.
Glympse – Share GPS location
Share a snapshot of where you are or get a view of your friends location.
Let’s be honest, tons of your friends are probably on facebook and that’s where they put their info.
Foursquare — Best City Guide
Share where you go, and check out where your friends go.