Shared Stuff should really be called "Google Share"; just read about Shared Stuff from TechCrunch in a post titled: Google Wants You To Share Stuff.

"…Shared Stuff is simple enough; users drag a “email/ share” button into their browser, and click it when they want to add pages to their Shared Stuff profile. Links can include an image, text extract, and/ or a user comment. The results can then be viewed directly, via iGoogle or RSS. An interesting addition is the option to use Shared Stuff to post links to other social booking sites as well, including Facebook Furl, Delicious, Reddit and Digg.

Friend can be invited by email, and bookmarks made by Gmail contacts using the service can be viewed as well."

I'll need to use it first to decide Shared Stuff is useful for me.