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.
I took advantage of the free morning travel whole of last year while I was still working in the city. It's great having to save $3.58/day, got me out of bed early for a morning workout at a nearby gym before starting the work day. Don't know why people complain about having to get up earlier when you can still catch a bit of snooze on the train.
It's a different story if you need to catch a bus to the station though, I still had to pay if I caught a bus to the train station which totally negates the benefit.
Still a very good initiative and I have a feeling it won't last long given the increase in weekend fares and tightening of 2 hour fares.