I nice idea, but an open source browser plugin with all local storage would fit my needs better.

I prototyped something roughly like this several years ago. I wrote a simple Firefox plugin that communicated with a locally running server written in Closure with a Clojurescript web app for browsing that used the same server backend. I stopped working on the because services like Evernote do a better job, at the loss of some privacy.

Edit: I didn’t intend to imply that Evernote reads or uses user data.