We have just updated a new diigolet that supports sharing bookmarks / annotations to your selected group(s).
We recommend that you completely reinstall the Diigolet in the Tools section this time (see instruction here).
Click Diigolet, after the menu drops down, usse the “Bookmark / Share” button to share to groups.
Diigolet is a lightweight but great alternative for those who cannot or don’t wish to download a toolbar, and for Safari, Maxthon, K-Meleon, etc. users…
Diigo 
I have the diigolet installed on Safari on my iMac – however I do not see the sharing options.
Colin
Click Bookmark, a pop-up window, there should be a share to groups field. If you still don’t see it, please send us a screenshot and your computer specs, we will take a closer look. Thanks