Friday morning's Glastonbury forecast

BBC weatherman John Kettley said heavy showers would hit the festival between spells of sunshine.

"I'm sorry to say Glastonbury's going to be pretty wet again this year," he said.

Mud has already started to make its unwelcome appearance at the festival site, although reports on Friday morning said it was only ankle deep. Last year's festival saw knee-deep mud pits swamping the site.

John Kettley's Friday Glastonbury forecast (0'12")

Within years the alternative free festival turned into a massive industry and bands covet a place on the billing for the event which annually takes over the Somerset farm.

Michael Eavis: Now all the bands want to play around Tony Bennett (2'01")

Artists taking part in this year's festival include: Primal Scream, Tricky, Bob Dylan, Robbie Williams, legendary crooner Tony Bennett, Portishead, Blur and the improbably named President Bongo and the Democratic Republic of Phonque.

Blur: Top popsters

The festival also boasts three nights of dance music headlined by the Chemical Brothers, Moby, Coldcut, Mad Professor and Roni Size.

And if that is not enough, visitors could take in a bit of entertainer Rolf Harris at the acoustic stage or visit one of hundreds of stalls and tents dedicated to anything from ecological projects to new age medicine.

This year will even see a World Cup screen and the festival's first ever opera performed by a group called Kiss My Axe.

Music Industry's Ascot

The 28-year-old festival has become known as the music industry's equivalent of the annual Ascot race meeting loved by the English upper class, where all the big names go to see and be seen.

The Spice Girls: Not appearing

While rival festivals have set up in recent years, few appear to be able to guarantee the continued success that Glastonbury enjoys.

Michael Eavis, owner of the farm and founder of the festival, has this year introduced a new luxury to the infamously muddy site which could rival the length of the queues for the toilets - a cash dispensing machine.

NatWest are taking a machine to the site and, in keeping with the festival's easy going image, are operating it out of a caravan.

As well as thousands of staff, police say there will be hundreds of uniformed and plain clothes officers on the site who will carry out random searches for drugs.

They say they will take a tough line on drug abuse at the festival with offenders facing swift court appearances.

Security staff will be aiming to keep visitors without tickets out of the site, aided by a 14ft steel perimeter fence.

Already an attempt to dig a secret tunnel into the site has been reported to have failed.

Glastonbury on the web

The event, which this year is asking people to sponsor saplings, will be simultaneously be broadcast over the Internet by BBC Radio One, in conjunction with the Guardian newspaper's Glastonbury Website.

Click here to find out more about the Radio One webcast.