Is there a Facebook API to add a friend? I can't find one, but then I can't find it stated anywhere that there isn't one, and this seems like something a lot of people would be asking about.
(Note: I'm not talking about a Facebook application, but rather an HTTP-based API.)
Clarification
I should mention that I'm trying to do this WITH the users authorization. They give me their username and password. Not trying to spam anyone.
Twitter has a very simple API for doing this; I'd hoped Facebook did too.