… by making a proposal for a barcamp presentation:
Proposals are submitted as comments, either on the barcamp page of our Developer Playground blog or on the barcamp pages on Google+ – in this case separately for day 1 and day 2. Proposals will be collected, sorted and published in our blog and on Google+.
… by contributing an idea for the hackathon:
Ideas and proposals for ongoing or new projects are submitted as comments on the hackathon page of our Developer Playground blog or on the hackathon page on Google+. Proposals will be collected, sorted and published in our blog und on Google+.
… by bringing cool hardware to show around, let others try out – or even hack?_