I've spent the last 6 months doing a lot of high level Architecture and API design. Most of my thought gathering, brainstorm and sense making exercises have involved a whiteboard.
Whiteboards are awesome because you can draw and express ideas easily and freely, but the sketches are hard to save and catalog. I've tried UML and digital white board tools and frankly the input mechanisms really cumbersome and slow down the whole process.
Is there any tool out there that leverages the freedom of a whiteboard, while still remaining digital?
Check out Rapido! by Ronnie Mitra. It's a personal project of his and it's not quite ready for production. But he was looking to scratch the same exact itch and developed something himself for "sketching APIs."