Here's an example of how it's been useful for me. Andrew McAfee is one of the most influential thinkers in a new movement dubbed Enterprise 2.0 (or social software in business), and just happens to be an associate professor at Harvard Business School - not a bad resource.
Now imagine being able to get a glimpse of what someone like Andrew is reading on a daily basis - what influences him, what he regards as important, what he believes is influential, bleeding-edge thinking.
I figured if I could guess his del.icio.us username I could SEE that. Andrew doesn't advertise his username publicly, although I do, and there are no rules about whether you should publish your username or not, but there is also nothing wrong or illegal about adding him to my network - by using del.icio.us he is automatically publishing his 'thought stream' - his IP - to the WWW.
To cut a long story short, I eventually guessed his username, added him to my network and have been enjoying inspiration from his brain ever since. If only Einstein had del.icio.us...
Add colleagues, friends or interesting strangers to your network. You can read what marketing demigods such as Steve Rubel or Seth Godin read. Provided you can guess their usernames (or email them and ask, or search del.icio.us for it) and if they use del.icio.us, you're sorted.
Once you've added a name to your network, their bookmarks will appear in the body of the page:
Hey presto - you have built a library of knowledge and resources based solely on the usernames of other del.icio.us users whose brains you admire.
You can go a step further than adding thought-leaders to your network and start to tap into the del.icio.us zeitgeist by subscribing to specific tags.
Click on the 'subscriptions' link at the top of your page - it's next to the network link we just worked on. Now think for a second... every piece of information every human that has ever used del.icio.us is tagged with freely chosen keywords. At the time that I published this, the del.icio.us tag cloud (the aggregated tags from every bit of info ever put on the site), looked something like this...
The bigger tags are more popular than the smaller tags (more bookmarks are categorised with those tags). The subscriptions section allows you to add individual tags so that as soon as anyone, anywhere in the world tags anything with YOUR subscribed tag, it's sent to your del.icio.us/subscriptions page.
Example - you love windsurfing, so you subscribe to the tag 'windsurfing'. Anytime anyone anywhere in the world finds a resource on the Net they think is relevant for windsurfers or windsurfing, and they tag it with 'windsurfing', you'll receive it automatically. I'll say it for you... Holy moley, that's pretty cool!
Now you've built up a tidal wave of links to resources and sites that are being generated by people you admire and trust, with tags you find interesting or relevant to you. You still haven't used del.icio.us to bookmark one single thing yourself, mind you.
In del.icio.us each page has an RSS (subscription) feed so go wild with syndication. Remember, too, that you can use these feeds to generate content.
Example - we run a site for a customer that is themed around customer service. So we've drawn an IP library of thought leaders in the customer service space in the networks section, of relevant tags in the subscriptions section, and deliver it to them as one, pretty, shrink-wrapped feed of pertinent knowledge, with shiny ribbons on it.
And the client loves it.
So if you're smart you're thinking to yourself, "Damn, I could use that in my company to harness the collective intellectual capital of my people. One time..."
If you're not thinking that, you might still be smart, but maybe a little slow. You see there's nothing stopping you from applying the principles of social bookmarking to every piece of information in your organisation. Be it emails, reports, policies, books, minutes - everything can be tagged, compared and collated with tags. Even if you don't yet get Web 2.0, then at least understand that tags are the Holy Grail.
del.icio.us doesn't yet offer a behind-the-firewall solution for business, but fear not, all is not lost: if you're interested in using a social bookmarking service like del.icio.us behind your firewall then try out Cogenz or Connectbeam.
As a last note to those of you in the social media consulting space; I use this demonstration in presentations to clients as a very succinct, powerful way to explain the wisdom of crowds theories in practical application for business. How tags work, how social networking works and how it all affects knowledge. Every single time to date, they are blown clear out of the water. It is my most effective sales tool by miles.
So there you have it, one of the easiest ways to take over the world: simple, powerful, del.icio.us.