What's Wapwap?

Anyone who employs that full Aussie accent and slang when they're talking to someone who clearly isn't from here is a bastard. I use the word Wapwap if I am halfway through a sentence and can't think of something else to say, he says. The next one is to do for a crust. That's one of those more... it's rarer. It's definitely used by real Aussies but not in everyday language.