I presented about tracking planes' ADS-B locations using an RTL-SDR dongle the fantastic Malcolm Robb fork of dump1090 running on a Raspberry Pi. It looks like he hasn't updated it since 2014 but it sill builds and works well on a Pi.
A fresh install of Raspbian comes with all the developer tools needed and you only need to install rtl-sdr and librtlsdr-dev to get what you need to make dump1090.
In my presentation I demonstrated a build and run of the software. The shed at Dural is rather well shielded and we only saw a few planes using the indoor antenna.
Peter, VK2EMU, showed a fantastic looking 3D CNC machine from China that he's building that costs about $200 and might be suitable for PCB fabrication. (Note that it's too early to tell if this is actually a good deal).
John, VK2ASU, is turning into a C programmer and showed a touch screen controller for a rig he's building.
Great to see everyone and thanks to John, VK2ASU, for the photo of me above.