Google Sidewiki is a very nice concept, but ReframetIt is a way better implementation of the concept. try http://www.reframeit.com, see it in action here
I have tried Google Sidewiki, and I have uninstalled it within the half hour, because it is missing the point on the user experience side, and it does not really deliver on its promise. Maybe the next version will be better. In the meantime, ReframeIt rules :-)
It is always nice to see Google push great new ideas, but in this case I think that they are victim of becoming too big for their own good. And they seem to be spreading themselves over too many things without really going into the depth of them enough to make them really worth our while.
I have seen it happen several time: friendconnect was a great idea, but I do not see too much happening with it, Google talk was a good idea, but I do not seem much happening with it, etc...
The worst of it all in this area is Google contacts, this link you have in Gmail to access your contacts. This is the worst contact management system I have seen, and it has not been improved a bit in the few years I have been using Gmail. And even if you use Google Apps and pay for the service you are very limited on that side, and for example there is no UI to upload contacts that you want to share with colleagues within the same domain. Just an API, and outside vendor who have built the HTML and will charge you for that piece. How hard can it be for Google to resolve this?
I love Google and I love what they bring us (I can't wait to see Google Wave open up to more people so that I can start use it fully to communicate), and I appreciate that they bring it to us for free, but I wish sometimes that they would do a little less and go a little deeper to make it really work...
Comment posted on Google Sidewiki at www.google.com using Reframe It