Creddon - Tweet for a cause and a sponsor will donate $1 to charity
WeAct - WeAct is a chat, task and organizing application for social activism and community outreach.
UpEffect - Crowdfunding for social good products
eSolidar - Charity shops and online auctions to support great causes
Nifflr - Use computer's processing power to earn money for charity
Public Design Vault - 500+ design tools for public good, all in one place