If you're willing to put in the time, you can export contacts from a variety of websites to create one big master list, as a .CSV file. You would then import them into Google contacts, for instance.

Mail, Gmail, Google Apps, and your other email accounts into Google Contacts. Next download your address books from LinkedIn, Facebook, Outlook, Orkut, and other accounts as CSV files and import ...

Simple webapp Friends to Gmail converts your Facebook friends list into a Gmail-compatible CSV file complete with birthdays, location, bios, work history, and hometown. What's the point?