my work colleague just buzzed me to ask if he could borrow some cash. I said yes as I trust him 100% and know I'd get it back. ASked for transfer details and he's gone weird.*

Only it turns out it's not my work mate, as I'm currently with him in the kitchen.

What shall i do with this scammer?

*we were talking online as it's an open plan office. As soon as he went into the kitchen i went to talk about it rather than do dealings on FB.

Tell him that you have just come into some big money via a Bank Nigeria lottery and that you can pass on some of your winnings to him if he gives you his bank details.
or arrange to meet in a dark alley and pawn him with biking accessories?…

Apparently it's the Facebook "money transfer scam"

I'm just stringing him along now.

Western union transfer is more faster apparently

"more faster than what" says i

a deals a deal mate. best pay up.

aye nicko. you're right.

So has this crook gained access to your mate's facebook account?

yeah – he'd not accessed it for about a year. Worrying eh?

it's gone offline now. My workmate has pulled the plug.

just done a google search as hadn't heard about the facebook nigerian variant scam before. found this great conversation some bloke had with a nigerian scammer pretending to be his friend:
Nigerian scammer hilarities