I have been mapping in Sydney from June 2009.
I live just out of Sydney in the northern part of the Blue Mountains near Kurrajong and commute each day through Syndney's north western suburbs to Silverwater.
There's heaps of mapping to do with all the recent housing estates around Bella Vista, Kellyville and Rouse Hill needing plenty of attention.
I regularly go camping in all different locations around NSW and have made it a mission to collect tracks on these trips and include POIs for many of the great camping spots around NSW.
I'm using a Garmin GPSMAP60CSx to collect tracks on foot, on the bicycle and in the car and I edit the data in JOSM with all the great plugins folks have written to make the job easy and fun. I also use OSM routable data in my vehicle GPS.
Get in touch if you'd like to organise a mapping blitz, many hands make light work !! north western Sydney needs you :)