Do you have an idea that doesn't fit any of the other challenges? This is the place for you, whether you want to design and develop an app, create a data visualization, hack on an Arduino... or anything else you can think of!
We are creating a low cost atmospheric probe that can recompile atmospheric data for cities that actually are facing troubles measuring climate data. We want to increase the accuaracy of the meassurements to predict natural dissasters.
http://chasat.blogspot.com/ Blog about homemade probes in spanish
hoimemade atmospheric probe