A good example of a “Web 2.0” site is del.icio.us. It’s a place you can bookmark all your favourite sites online, so you can can access them anywhere you log on. However, it actually provides much more than that. Central to its design is the concept of tagging – marking each entry with one or more short words describing what it is about.

That opens up all sorts of possibilities. For example, I’ve got an AJAX tag, which I use when I record a site that touches on that strand of web technology. However, I can also see all the sites that other people have tagged as being about AJAX. Suddenly it becomes a tool not just for saving what I’ve found but also discovering what related material other people have discovered.

Another application is in creating a wishlist. You can do this on Amazon but only for products you can buy there. With a del.icio.us wishlist, I can mark anything I can find on the web (although, if you want to buy me a present, please note that I haven’t fully exploited this concept yet – my wishlist doesn’t cover many of the items on the hidden giftlist I’ve been manually publishing for ages).

The other thing that marks del.icio.us as a Web 2.0 site is that you can easily extract information from it to use in other places. The URLs I’ve given above follow such obvious patterns that it’s possible to guess them. Another example is the tagroll, a little bit of javascript that provides a visual map of all my links:

It’s very compact but laden with information – the more frequently I’ve used a tag, the larger and brighter it becomes. I’m planning to exploit this system to provide a way of digging back through all my previous blog postings (almost 150 so far and starting to become a bit hard to dig through). I’m using a very simple blogging tool but I can now mix in a touch of del.icio.us and open up a range of new options.

Tags: web2.0, del.icio.us, tools, futureofwebapps