Picking up where del.icio.us fell down is Diigo.  They have received a little buzz recently for their V3 beta release.  It is a very impressive application.  To call Diigo a social bookmarking site would be to limit it to a box that it has grown beyond.

This application gives you everything you would expect from a bookmarking application.  You have tags, toolbar, bookmarklets, widgets and a ton of other tools to make life easy.  You can share bookmarks and connect to friends and even communities.  And it all works fantastic even if this was all it did.

Diigo goes beyond all of that.  You can comment on links, thus enabling conversation.  This is sorely missing from del.icio.us and it is weakly implemented in Mag.nolia.  You can schedule a link post to your blog or simply post a link directly.

As if enabling a conversation on a link wasn’t enough you can actually highlight passages or add annotations right on a page.  All of which can be shared.

Though most will likely give a collective groan to a new bookmarking site, if you aren’t using Diigo you might as well be living in a web 1.0 world.

Diigo does have a couple items I would like to see worked out.  First of all they didn’t get the memo that we have reached the mobile tipping point.  I would love to see an iPhone version of this so I can use it on the go.  Where is the API?  How can you have a service in today’s market place without an API.  Finally, trackbacks.  Let me carry the conversation back if I can.  So many social sites don’t implement this and it seems vital to enabling a conversation.

I know all the A-listers have glazed eyes over friendfeed right now, but they are really missing out if they don’t try Diigo.