The good:
Diigo imports bookmarks from elsewhere; tags pages by topic; lets you mark up and share Web pages; has a simple interface; toolbar and bookmarklet allow quick bookmarking; bookmarks simultaneously to rival services; searches text and comments within bookmarks.

The bad:
Diigo's subscription features are under construction; doesn't automatically merge similar tags; doesn't preview bookmarked pages.

The bottom line:
Diigo lets you save, import, tag, highlight, mark up and share Web pages--offering more advanced research tools than Del.icio.us.

To use the highlight and find feature, you just type in the textbox that you use for normal searching but this time either click on the button for each word of the search term or the highlighter button. It sounds like a lot involved with the toolbar, but really once you start to use it, you will grow to love it.

I mentioned that Diigo is not only a social bookmarking service, but also a social annotation service. Diigo lets you highlight any text on any site and bookmark the page saving the highlighted text. Once the bookmark is saved, the next time you visit the bookmarked page, you will still see the text you highlighted, but this time with a blue underline. You can save multiple highlights on a page and even save sticky notes to each highlighted text area that you saved. This is excellent because there are many times that I have wanted to keep a note of something specific on a site and couldn’t and later on forget why I bookmarked it in the first place. Now I can keep notes on pages so I know what I was thinking at the time. On top of all of this though is that you can set public sticky notes. Meaning that when a Diigo user is to set a note to public on a page, any other Diigo user will see the note as well when viewing it. I also should note that in order to save a public note, you must have atleast two friends to help cut down on abuse with notes on sites.

Diigo has many other great features. One feature that caught my eye was the importing of bookmarks. Instead of importing a saved file to Diigo, it will actually open a popup listing all your bookmarks from your browser and let you import each on all at once or individually. It also tags them all by default using the tag, “Links” along with the name of the folder it was found in from your bookmarks directory. This is great because I don’t have to make any file or anything to import bookmarks. Another feature that I thought was interesting search page for Diigo. Diigo has searching in the interface itself, but unlike other services, it also has its own search page that lets anyone search Diigo (even if you aren’t a member). Instead of showing results in the Diigo’s website itself, it will show results on a page in a format much like Google’s which makes it a whole lot better, in my opinion. Another feature that Diigo has is friends. You can add friends to your bookmarks page so you can easily view their bookmarks when you want.