Less and less over the years but they still add bits to it, just not the comprehensive reports they used to.
Anyone really interested in learning the TRUTH (that's the real truth BTW, not the alien BS) should consider buying
'The Field Guide' by Rob Irving and John Lundberg. It's an entertaining read and pours much cold water on the 'scientific analysis' done by Levengoode (he's the guy who developed the microwave blx theory), as well as destroying the myths that have inevitably driven this particular branch of woo.
As for the Alien Face/Disc at Crabwood.
It was made over three nights... It was a very complex and time consuming job and so it was decided (by the people who made it) to make it away from the usual crop circle hot spots of Avebury, Alton Barnes etc.
Busty Taylor (crop circle researcher) found a LED torch with a green bulb on the day of it's discovery (there is a photo of it on the web somewhere but I can't be assed looking for it right now).
As for the overall style of the Alien, it was a theme for a while making halftone faces and in this case a face made up of lines.
A series of adverts were done using similar technique for Orange and one for Richard & Judy the same year.
http://www.circlemakers.org/orange.html
http://www.circlemakers.org/richardjudy.html
And as I seem to be getting a reputation for silly pictures... And people are always asking how can people possibly make crop circles without leaving any signs of human involvement... Here's the answer:
[qimg]http://i246.photobucket.com/albums/gg117/ThePsychoClown/HoverBootsAd.jpg[/qimg]