It's intriguing that Diigo uses consecutive Is. You just don't see that very often...
But, back on track.
I started using Diigo to bookmark sites on the web, and I think I like it. I bookmark TONS of sites normally, but they're all tied to whichever computer I happened to bookmark them on. I've experienced plenty of frustration when I couldn't access my bookmarks from a different computer. So, this will fix that problem. I love that I can access my stuff anywhere. I like the toolbar/sidebars that allow me to view my bookmarks along with webpages.
I still have to explore all the options, but I'm using the basic tools of Diiigo and enjoying them. :-)