Term derived from slang. Normally used in England. I mean you'd sound like a bit of a nob if you used this in America or something.
Anyway, basically it translates to "What's up? You're extremelyattractive" It is now mostly used by teenagers who are wannabe gangsters (like I stated earlier) or a group of guys saying it as a joke.
wagwan is a jamaican patois or jamaican english way of saying "whats up"
piff means "high quality", and ting is the autistic version of saying "thing"
a bbm pin is the numbers you'd use to contact someone on the blackberry messenger