If you were on one of the flights grounded by Qantas during last year's industrial dispute, take note: today is the last day to get a refund on any flight that was cancelled during that period. Many people (myself included) put off doing that at the time because the phone lines were so busy, but January 31 is the final cut-off.
Provided you have the original booking reference, the process seems straightforward; I got through the whole phone call in just a couple of minutes. Note that this deadline doesn't affect the bonus free return flight Qantas offered to affected passengers. If you've received a voucher for those, you need to book them no less than 14 but no more than 90 days in advance, and take the flights before December 14 2013.