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!