I have been blogging at wordpress for the past 6 months and very recently i came to know about the flash cards. Can anyone let me know as to how to activate flash cards in wordpress. I tried going to the "extras" option but then i can't see anything regarding flash cards over there.
Are you talking about the hovercards for gravatar users? It's available on WP.com, not for self-install sites. However, there's a fairly easy hack to get it working anywhere.
See this article: http://ottopress.com/2010/gravatar-hovercards/