Zac Goes Down Under

G'day Zac!

The "HSM" hottie was in Sydney, Australia on Wednesday to promote his new film "17 Again." In the comedy, which opens in the U.S. next month, Zac plays the teenaged version of Matthew Perry. A freak accident de-ages him from 37 to -- yep, you guessed it -- 17.

Zac brought out hundreds of screaming fans, but it was Taylor Swift's red carpet arrival that left tongues wagging. You see, Taylor doesn't appear in the movie. She's not even on the soundtrack to my knowledge! She just happens to be in Australia touring and promoting her album "Fearless" and decided to drop in at the premiere.

The country cutie is definitely "fearless" for posing with a spoken-for man! Taylor and Zac look good together, but I'm sure Vanessa Hudgens will have none of that!

Check out the trailer for "17 Again":