I spent most of this weekend listening to uber-designers like Josh Davis and master guru Erik Natzke at OFFF. Suffice it to say, these guys are amazing at what they do. I also heard founders Dan Phiffer and Mushon Zer-Aviv describing their new project, ShiftSpace.

ShiftSpace is basically an open source plugin, primarily for Firefox, that allows users to create a second layer of information that floats above any webpage. Users can highlight text, embed video, leave comments, and create link trails on any website. Doing so doesn’t disrupt the original page at all, and any other ShiftSpace user who logs onto that page can interact with the previous “spaces” (ShiftSpace’s name for these notations) left by other users. While the interface is a little clunky — it is still in its infancy — ShiftSpace provides the best approximation of truly social web browsing that I’ve seen yet.

They’re also offering development grants through Turbulence.org, so if this sounds like its up your alley, get over there and help them make it great!