Is there a way to retrieve a facebook chat?

I was chatting with a friend using facebook’s built-in chat interfacet the other day and he gave me his phone number. I can’t find where I wrote it down. Is it possible to retrieve that chat transcript somehow?

It doesn’t really help, but if he’s ever online again you can click his name and see your chat history. Which means it’s saved somewhere on your hard drive or on a Facebook server. I can’t tell you which way to go from there, but it’s a start.

And upon searching Facebook for answers, I came across these relevant groups:

We Want History of Chat!
Petition to Save Facebook Chat History
We Definitely Need Facebook Chat HISTORY!!!

Like I said, though, it has to be saved somewhere, because when I click on somebody’s name to chat, I can see what we talked about last time, even if it was several days ago.

The official word from Facebook: