You may wish to consider Plaxo. It is a free internet service that sync address books between different people who “know” each other. In exchange for the information you share with them, which I am sure they have various ways of making a profit on, you not only get up-to-date info on fellow Plaxo “members”, but you get a usable web-based address book which is a backup of the address book on your computer. It will even sync multiple machines. I have found it a great tool. Some call it “Faustian”, but:
(1) They are upfront about they reuse data. Everyone does it but are not honest enough to admit it.
(2) I seeded my address books with fake people (i.e., my non-computer literate elderly uncle complete with an isp email address). If spam was to show up in the email boxes for my “fake people”, then it could have only come from them. And, I’d rat them out to the inet community. If it sounds like “trust but verify”, it is. I did a few tours in security, so I am very skeptical of stuff on the net. Wanna see my tin foil hat?
FWIW
Reinke Faces Life 