I like the idea, but i'm a little annoyed by google on this one. First of all I use firefox 2 and 3, chrome and IE on multiple different computers. Three home computers, a laptop and a work computer. So in order to see this added content I have to install a toolbar on all of these and I don't install googles toolbars ever. The fact that it doesn't work in Chrome, googles own browser, is even more annoying. So while I think the idea is great, the implementation is certainly a no go for me and I'd bet others as we wont have the right toolbar and/or browser installed at all the places that it would be usefull.
Instead of all this, could we get CPAN updated to include the sidewiki gadget in some way? Maybe a good group of beta users could use the toolbar, add some content and then convince the powers that be to add the widget? I dunno. I do appreciate your zeal and zest though, it is nice to see someone this passionate about it all!