Contact Share is one of the application Nokia introduced in WP8 summit and as of today that application is available for your Nokia Lumia phones from the Marketplace.
Apps premise is simple. Contact Share simply lets you send contacts via email or SMS and you can send the contacts to any phone, be it Symbian, Android, iOS and BlackBerry in Vcard format.
For some reason my Lumia 800 is giving me error as i open the app saying that my firmware version isn’t new enough to run it. There are some who have reported this as well, but most do not seem to have problems installing the app.