For all you PCVs out there, do look over Water Charity's website: this initiative is designed especially for PCVs to be able to quickly and easily address clean water issues within their communities. If your community has need of such a project, I highly recommend applying for a grant from Water Charity. The application and reporting processes are intentionally very simple and straightforward so that your community can have access to clean water as quickly as possible.
For everyone, look around on Water Charity and consider donating to help another of these worthy projects, conducted by PCVs in communities around the world!