Guess Who This Australian Stud Is!

We all know the stars shine brightest in L.A. (when there isn't light pollution) ... but there's plenty of thunder down under -- can guess you who this Aussie stud is?

We caught up with this singer-swimmer-actor at LAX, and when we asked him if he'd be interested in buying a suspiciously phallus-shaped house down in Sydney -- he described the house as an architectural "breakthrough" -- he said he'd have to grab it ...