There are several archives of sermon audio and text on the Internet from well known speakers which are worth plundering for their riches. Use them for sermon audio on long car trips, or to listen to while ironing. Search the archives for sermons on specific topics or passages of scripture.

Here is a selected list of sites to start you off:

Desiring God (John Piper, also includes free books)

European Leadership Forum (various speakers, including Bruce Winter, Ravi Zacharias, Peter Jensen)

SydneyAnglicans.net (Peter Jensen, Al Steward, John Dickson, Simon Manchester and many more)

St Helens, Bishopsgate London (various speakers, including Dick Lucas, Don Carson and many others)

TheResurgence (podcast and vodcast; various speakers including Don Carson, Timothy Keller, Mark Driscoll)

Mars Hill Church (Mark Driscoll; at times controversial in the USA because of his turn of phrase and "crudeness", but possibly not much different from the language of Australian culture. Very direct and hard hitting)

Redeemer Presbyterian NY (Timothy Keller and others; most sermons must be paid for, but the free samples are well worth hearing)

BiblicalTraining.org (online theological education)

Reformed Theological Seminary (online theological education, lectures via iTunes)