I attended the Software Development Summit December 2013 in Helsinki.
I was fortunate in being asked to perform a keynote, and asked to fill in for a keynote speaker who unfortunately couldn't attend, so I did two keynotes. Lucky me.
You can find slides for the talks listed over on my Compendium Developments site.
I managed to catch up with Kristian Karl and learn more about the CI and testing regime at spotify, you can watch his Eurostar conference Experiences of Test Automation Webinar online (Q&A).
I was able to quickly hang out and see a few of the twitter enabled attendees: Johan Atting, Johan Jonasson, Aleksis Tolonen, and my fellow Eurostar Committee member Maaret Pyhäjärvi
I did receive a pointer to FreeNest - an open source platform put together by students which is designed to help teams get up to speed with a set of collaboration tools on Ubuntu quickly.
But it was all over very quickly and I had very little time to chat with Ilari Aegerter or Gojko Adzic.
The only downside I had was that I had to miss Gojko's Keynote because I thought I was flying out early. Of course the London Fog had other ideas so instead of learning from Gojko, I was stuck at the airport instead of enjoying the end of the conference :).