I've never seen or heard of these before. They have a decent number of locations (one is quite close to where I live). I'm not sure why they are not pushing this harder. Having to pick up a parcel from their stores between 9 - 5, monday to friday is the only painful part of using AusPost.
FYI some post offices, in NSW at least, have an "early bird" collection window for parcels and PO Box holders. My local opens from 07:30 to 08:30 IIRC. Handy for avoiding the queues.
I was one of the early adopters of this service. The trial (which I signed up to) started in March of 2012.