Bowing to the inevitable, Microsoft took a big step today towards data portability by announcing that Windows Live contacts can now be exported to social networks and other Websites. Its Windows Live Contacts API will work with Facebook, Bebo, Hi5, Taged, and LinkedIn to start. Members of those social networks will be able to import their Windows Live contacts (i.e., their Hotmail address book) so that they can more easily find or invite those people into their social networks. Microsoft is also launching a site, Invite2Messenger, for importing social networking contacts into Windows Live. Right now that only works with Facebook.

Although Microsoft is part of the Data Portability Workgroup, this is a separate effort, confirms a spokesperson. So much for industry standards. But this is an important step in allowing people to take their contacts with them no matter where they reside, whether in their email or social networks. Instead of startups scraping Hotmail to ingest contacts, now they have a legitimate way of doing so.

In a way, this is a bit of a catch-up move. You can already import contacts easily from Gmail into services such as Facebook, Friendfeed and others. Maybe Microsoft had a touch of Gmail envy or were concerned about being left behind. At a certain point, an email service that doesn’t let you export your contacts could really be a damper on your social life elsewhere on the Web.