Looping - Fast community feedback on all your designs.
Conceptzilla - Get competitive design for a fraction of the industry cost
Visualtip - A service that allows designers and clients to annotate and collaborate on images in real time
Brace - Access to the best developers for $0
LimeSurvey - LimeSurvey: the Online-Umfrage Tool - Open-Source Suryeys
Unified Tools - A unified collection of useful online tools