You know that a new idea has become trendy when it appears on a television soap: Grange Hill recently ran a storyline about a school kid who got into trouble after posting personal details on their 'blog'.

The Guardian newspaper is obsessed with blogging and publishes regular articles about the subject. And, needless to say, there are awards for blogging, known as the Bloggies, which can be seen at www.fairvue.com.

We have to confess that we're not entirely sure what all the fuss is about. After all, a blog is little more than a variation on your own personal home page on the internet. You use the blog as a kind of online journal or diary, where you write about things that are happening in your life.

There's nothing particularly groundbreaking about the idea and many of the countless thousands of blogs on the internet amount to little more than the tedious outpourings of people who really should find themselves a decent hobby. One well-known blog recently thrilled us with the headline: 'Mockingbirds are everywhere in Austin and they're very loud.'

Every now and then, however, a gem emerges from the mundane mass of trivia. One big winner in last year's Bloggies was actor Wil Wheaton, who played Wesley Crusher in Star Trek: The Next Generation.

By publishing a blog that actually displayed a sense of humour about his years on Star Trek, the actor has managed to gain some credibility, plus a huge following for his website.

The site, at www.wilwheaton.net, also highlights another interesting aspect of blogs. As well as rambling on about their personal lives, many of the best blogs contain links to other websites or interesting news items.

In fact, many blogs now focus almost exclusively on providing news and information links, often with a focus on a particular subject. If you can find a blog that shares your own interests, it can act as a kind of alternative news service.

The basics
The word 'blog' is just an abbreviation of web log. In other words, a blog is simply a web page that acts as a kind of online diary where people write about their daily lives, or about subjects that interest them.

There is a vague definition of a blog, which is that it contains multiple short items, arranged in chronological order and updated on a regular basis. However, that definition is loose enough to provide plenty of scope for experimentation.

Some people put poetry on their blogs, some people discuss politics, music or any other topic that they're interested in. There are also many specialist blogs, such as U2log, which has become a popular news and discussion site for U2 fans.

There are quite a few amusing blogs and a handful that actually manage to be interesting or informative. Some of the best, such as London-based Barbelith, can turn into professional looking web magazines.

Unfortunately, for every good blog, there are invariably a dozen boring ones, so there's plenty of chaff to sort through before you find the good stuff.

Why you need to know about blogs
At the moment, most blogs are the personal writings of individuals. Some of them can be quite interesting, especially as a way of finding snippets of gossip and information that don't always appear on conventional news services.

But it's the future of blogging that is currently attracting most attention. Google, the current king of the search engines, recently bought Pyra Labs, the company that makes the popular Blogger software. Blogger has hundreds of thousands of users, which represents a vast amount of information that Google can sort through in order to improve the quality of its search results.

There's also speculation that Google might develop a corporate version of Blogger that allows business users to maintain internal blogs for sharing information, or as an alternative to traditional email.

The science
At its most basic a blog is simply an online diary, so all you really need is a word processor to write down your thoughts, then save them in the HTML format used to create web pages. That, however, would just leave you with a page containing large, unstructured lumps of text.

Like any web page, a good blog needs structure, so most regular bloggers use special software designed with blogging in mind.

These special programs act like a database, allowing you to divide your blog into categories you can add to and update on a regular basis. The blogging software will then automatically update your web pages.

It should also handle tasks such as uploading the blog onto the internet and providing links to other blog sites. Popular blogging programs include Blogger and MovableType for the PC, and iBlog for the Mac.