I finally got around to signing up to del.icio.us! I’ve been watching the progress of the service for quite a while now but not felt motivated enough to sign up and start using it.

For those of you who don’t know

del.icio.us is a social bookmarks manager. It allows you to easily add sites you like to your personal collection of links, to categorize those sites with keywords, and to share your collection not only between your own browsers and machines, but also with others.

But it is much more than that. I’ve used on line bookmark managers before, but my use of them usually tailed off. My del.icio.us bookmarks are already promising to be much more useful than those. My final push to start using the service was motivated by two things. First, the ability to store my bookmarks on line: I have been bookmarking a lot of sites recently. I’m on a new PC at my new job, and whilst I could import all my old bookmarks, I decided not to at this point. It has meant that I have found a lot of more up-to-date resources than I would have perhaps used. Because of this I have found myself emailing lists of links home to myself using Gmail.

This brings me on to the second reason I decided to use del.icio.us: Keywords. I really like Gmail’s labels (keywords) and have been adding lots of labels to my emails, and using Gmails great search capabilities to filter on them. Del.icio.us’ ability to add arbitrary keywords or tags to your bookmarks as well as comments is really great. You can add multiple tags to each bookmark (a simple pop up “add this site to del.icio.us” bookmarklet is available), and then filter your links on those tags. I will be making good use of that feature.

That brings me to the other great things that del.icio.us does. The social side of bookmarking. It’s incredibly simple yet powerful. When you add a bookmark, it appears on the del.icio.us home page along with your login name, your comments, and the tags you assigned to the link. That feature alone is great. You can simply watch the home page (it’s available as an RSS feed) and see what other people are linking to. You will quickly find lots of interesting sites just doing that. On top of that you can click on the login name of the person posting the link and see what else they are linking to. You can also click on a tag and see what else they linked to under that tag.

Now, let’s go back to the link you added yourself with your short list of tags. The display of that list also tells you how many other people have bookmarked the same link. Click on that and you get a list of those people along with their comments on the link. Now if someone else was interested in bookmarking the same site as you, what else might they have bookmarked? Click on their name and you get to see their bookmarks. It’s another great way to find related links to the same stuff your are interested in. On that display of your bookmark you also get each of your tags as a link. Click on that and you get to see all the links to which you assigned that tag or keyword. But you also get a link to “‘your-keyword‘ from all users”. Click on that and you get to see all the links other people have categorised with that same tag. This is really powerful.

John Udell has some great thoughts about using del.icio.us to categorise his own blog posts and research resources as well as incorporate del.icio.us into his category searches/data mining experiments.

Which brings me to some other great features of del.icio.us I want to mention: It implements a simple REST API, RSS and HTML feeds, and subscriptions to tags, searches, and more.

I think if I can harmonize my del.icio.us tags, my Gmail labels, and my WordPress blog and link categories into a comprehensive taxonomy, I have the makings of an incredible data repository.

If everyone did that and if you throw in other systems like Technorati to perhaps add relevance weighting to your filter/search results, a touch of GeoURL to filter on geography if required and soon you could have a significant piece of the semantic web. At least something with huge potential. Layer a natural language query processor on top and the mind boggles at the potential.

A couple of other points. Del.icio.us was written by Joshua Schachter who also wrote GeoURL. I recently discovered REST and was quite intrigued by it only to find that, in essence, it’s what I’ve been doing with my web apps for the last few years!