Masses of info and speculation relating to the recent Darvill / Wainwright dig, on the BBC Timewatch web site, and a series of ongoing discussions on the Open University site:
bbc.co.uk/history/programmes/stonehenge/
open2.net/forum/showthread.php?t=4502
The following might also be of interest -- particularly with respect to the enigma of the bluestones:
Bluestone web site:
netcomuk.co.uk/~brianj/bluestones59.html
Glastonbury-Stonehenge link?
mypembrokeshire.com/vnews/display.v/ART/2006/12/21/458ad107451ca