We got word last night that Diigo will be releasing version 3.0 of its social bookmarking and webpage annotation service today. The company is calling it its biggest upgrade since 2006, when former TechCrunch writer Marshall Kirkpatrick gushed extravagantly over it.

I’m personally not a daily user of Diigo, even though going back and reading Marshall’s review makes me think I should be. I’ll just have to try v3.0 in full later today. A demonstration video, embedded below, shows an entirely new user interface. We’re also told that the code has been rebuilt and over 100 new features have been added. Social networking has been further developed, too, so you can share your bookmarks with friends and groups more effectively.

Diigo is explicitly pitting itself against Delicious by stating: “in the battle field of social bookmarking 2.0, we believe only delicious and Diigo are still strong players, with Diigo clearly the leader in terms of features and innovations…People who have seen both Diigo 3.0 and delicious 2.0 also think that we are far ahead of delicious 2.0.” Sounds like Diigo’s trying to play David to Yahoo’s Goliath.