There were nice talks in the morning showing off some great and useful astrophysics-related engineering. One highlight for me was Thomas Robataille (Harvard) showing off new ADS-related awesomeness. He mentioned the point that interfacing with ADS through command-line tools improves repeatability. Amen to that! Another highlight for me was Thomas Boch (CDS) showing off the next generation of insane CDS tools.
[Note added later: The next day we won a runner-up prize in the Hack Day awards. Some of the submissions were incredible; one of them got press coverage. My favorite hack was a home-built pen-casting system (draw and record voice and drawing in real time to tell a story).]