Being a celebrity can be tough. To keep yourself hot and in the headlines, you have to make sure that you are regularly 'papped' leaving the most exclusive nightspot in town, or seen on the arm of someone who's almost - but not quite - as famous as you.

But a new way of measuring celebrity is evolving, thanks to the internet. Anyone who's anyone will, of course, have their own official website, from Robbie Williams to Keith Harris.

Just as businesses use the net to promote their products and services, so those in the public eye use it to promote their latest film, show, book or album.

And there are absolutely thousands of official websites, some good and others seemingly posted online as an afterthought. The net is also host to legions of fansites created by fans for fans and usually independent of the artists themselves.

But, in our celeb-obsessed society we also like to know where the biggest stars hang out, what they're up to and what skeletons they have hanging in their closets.

There are plenty of magazines on the shelves that deal with gossip, rumour and celebrity scoops, but many of the most tantalising titbits can be found on the web.

The online grapevine offers many exclusive snippets (of varying degrees of truthfulness) about the secret and not-so secret lives of the biggest names in sport and showbiz.

Read on to find out more about the precarious relationship the stars have with the net as we visit the best (and worst) celebrity websites, as well as the sites the celebs would rather you didn't see.

Make it official
When you want to find out more about a particular celebrity, your first online port of call should be his or her official site.

Here, you'll usually find a selection of biographical information and, if you're lucky, a smattering of multimedia, such as images, video and audio clips.

On an official site you can guarantee that all material is legal and that any information you read will (hopefully) be accurate.

Frequently visiting a good official site can also give fans the sense that they are connected to the star. This is particularly true in the case of David Bowie's official site, BowieNet.

As well as establishing his own ISP, Bowie has set up an exclusive online club for fans who are willing to dip into their pockets.

Sign up to BowieNet and you not only get access to the man himself courtesy of Q&A sessions, David's online journal and the regular visits he pays to the site's message boards, but you get access to exclusive content, including music and videos.

Robbie Williams, too, rewards his fans for their allegiance. Register with the Robster's free 'inner sanctum' and get a heads-up on buying concert tickets, and gain exclusive access to content including web chats and images.

Although when we visited, the site said that Robbie was on holiday in LA, which may explain why he was not breathing down his web team's neck and demanding to know why his tour information was so out of date.

However, not all official sites will give fans what they want. On the one hand, ex Mickey Mouse Club members Justin Timberlake, Britney Spears and Christina Aguilera give their fans access to great images, 30-second streams of songs and various cool downloads, such as screensavers and wallpaper.

But even a massive star such as Will Smith, who has a career that spans both music and film, has a site that does not seem to adequately reflect his work.

If you are a fan of Will's albums, the site has made sure that you are pretty well catered for with plenty of music video streams, but film buffs will probably be disappointed with the brief synopses that sum up his acting career.

Miss independent
Independent sites serve a useful purpose for fans, particularly if a star is not very well known or isn't part of the current jet set. For instance, Diana Dors may once have been considered the British Marilyn Monroe, enjoying the adulation of thousands.

These days, of course, there's little hope of an official website for the busty star of such films as Yield to the Night. Step forward The Diana Dors Memorial Homepage.

This site contains a detailed biography plus enough movie and glamour stills to help preserve Diana's legacy.

Fansites can often be even better than their official equivalents. For example, your favourite band's official site is likely to be regulated by their record company, which has their client's image to look after.

Depending on the record company and the act themselves, the official site could be little more than a bit of online puff to promote the latest single or album.

And you can certainly forget about seeing dodgy pics from the star in question's past, or messages from old school chums relating stories about what your idol got up to in the classroom.

Hunt around the web for a good fansite and you might be pleasantly surprised by the range and wealth of info on offer. Take Fame Academy winner Alex Parks, for example.

Her official homepage is perfectly adequate, but is entirely eclipsed by the Alex Parks Online fansite.

Once registered at the unofficial site, you can swap Alex stories in the extremely busy forums, and you will see that dedicated fans have uploaded video clips of TV appearances, music, personal snaps taken of Alex at various gigs, and scans of magazine articles.

"We are a fansite for Alex Parks and aren't in contact with Alex, Polydor Records, BBC, or anyone else related to Alex," explains the team behind Alex Parks Online.

"We are just fans and decided to set up the site back in August before Alex had even won Fame Academy.