Spootnik lets you edit your tasks via OmniFocus' native apps, Spootnik's web front-end, or Basecamp. Spootnik's creator explains:
I use OmniFocus to capture and organize my tasks and Basecamp as communication platform. They are great and help me keep my inbox empty. But I really missed a link between them. It would be great if some of my OmniFocus tasks would automatically appear inside my Basecamp account and vice versa.OmniFocus' online synchronization feature gave me a broad hint to build a web application that connects these two worlds. You neither have to run a computer nor to install anything. If you, for example, update a task on your iPhone, it flows directly into your Basecamp account and your Mac's OmniFocus database. Simple like that.