Check out the Revolutionary Minds guest blog. It is worth browsing through.
They invite people to comment on interdisciplinary questions of very broad nature.
Current topic is:
Cross-disciplinary work has sparked provocative new technologies, solutions, and insights. What problems do you see as ripe for cross-disciplinary research, and which fields would you choose to combine?
Previous question was:
The boundaries of science are continually expanding as scientists become increasingly integral to finding solutions for larger social issues, such as poverty, conflict, financial crises, etc. On what specific issue/problem do you feel we need to bring the scientific lens to bear?
More will be coming.