The Easybeats, 'Sorry' (1966) - Boing Boing by Decius at 4:13 pm EST, Jan 23, 2009
Great garage mod punk from The Easybeats (1966). According to Frank at Save vs. Death, "George Young, the rhythm guitar player, is the older brother of Angus and Malcom Young and produced the first six AC/DC records. How's that for an awesome pedigree?" There's a family resemblance for sure!
This thread contains an collection of YouTube videos of Aussie rock that seems to collectively cover the gap between the beatles and early 90's grunge bands. A few interesting tracks in here.
Although not Aussie, this video from the Monks in particular is amazing for it's time.