"Chemnitz Linux Days" is one of the main Open Source and Linux conferences in Germany, for the 15th consecutive year now. And personally it's one of my favourite conferences.
Based on experience from the past two years I decided not to have a booth, but nevertheless submitted two talks. One was accepted: "Replication with PostgreSQL" (slides and script here). On the laptop keyboard&mouse: Andreas Kretschmer. On the microphone: me. It was the first talk in the morning, but the room was full with visitors. We got nice feedback about the talk as well and had to continue discussions outside of the room, when the next talk started.