This has been around for sometime now, however I can't find anything on Ozbargain and I know some people aren't aware that it applies with Myki.
Free travel on Melbourne's electrified train network for trips finishing before 7.00am (weekdays). However technically it is before 7.15am exactly. I believe they have done this with Myki to allow for trains that are late. If your train arrives after this you will be charged.
You need to have a Myki and positive balance. You need to touch on and off and you wont be deducted anything.
If you only train into and from the city then this essentially halves the cost of your travel as you only pay for a 2 hour fare.
From 2011: Passengers give free morning travel the flick
It's not that easy to get up so early esp if you have to work till the regular end of the day. You either have to go to bed early or give up an hours sleep!
You will grow to despise people who have late arvo meetings (esp if they are unproductive like most) and the fact that people think you always leave early (work less?) because there is no one in the office to see you do an hours work before everyone else! ;-)