Someone online was using the nick "Ninedynine". The conversation went sort of like this:
Her: Yes, I'm sort of a secret agent.
Me: Well, if you keep telling people it's not much of a secret is it?
Her: Oh, you're right! I need to work on my stealth. Sorry.
Me: Don't apologize to me - I'm not the one who Libby'ed you.
Admittedly, not a verb one gets to use often in casual conversation, but feel free to try it out.
(EDIT: cos got it submitted to urbandictionary: http://www.urbandictionary.com/define.p