A suggestion: Offer bounty to security researchers for increasing security and decentralization of the bitcoin network and software.
Security bounties are easy and effective for centralized organizations but difficult and less effective for decentralized projects like Bitcoin. Perhaps somebody could start a Bitcoin security bounty pool, where the time and amount of donations are displayed publicly. I think the task would be better suited for someone interested in creating and running such a pool rather than people who are more interested in plain ol' development. The person running the pool should ideally already have a reputation, but I suppose given enough time, that could be established regardless.