I think I'm about to explain what your asking about, LOL.
In blogging, anyway, a meme is when you write a post - usually with a question of some sort - and specifically call out on other people to answer it. Almost like some of the email chain things, but not really :P
With a lot of the blog software if you link to someone else's blog, they get notified... so they know that you "called" on them to respond to your post! I've been called on to respond to a meme post once (and then of course called out a few other names in my response post) - it was a lot of fun! :)