Looks like both Yahoo and Google can read vCards (defined by Microsoft as "The Internet standard for creating and sharing virtual business cards.")
Google now has a "view as HTML" version of the vCard. For example, here is someone's HTML version of the vCard format. Please do not call them. :) So Google is now reading these vCard formats. Here is one example where the exclusion protocol in the robot.txt file comes in handy.
Forum coverage at WebmasterWorld.