When executing a "clean run" of Eclipse (typically, after p2 has completely messed up your installation and you've lost critical functionality / plugins -- the only reliable remedy I've found thus far, is to wipe ~/.eclipse, and restart from scratch) the 'Available Update Sites' is an empty list.
Googling the information proves every time a complete random shot in the dark, so I thought I'd collect the info once and for all in a place I'm likely to find again in the future.
The wiki page (impossibly difficult to find in the maze that Eclipse documentation is):
http://wiki.eclipse.org/Eclipse_Project_Update_Sites
Gives this link for...
The Eclipse Project Updates - http://download.eclipse.org/eclipse/updates/3.7
Executing an update of the Eclipse Platform, adds another 'update site' that provides a much
richer selection of available plugins:
Indigo - http://download.eclipse.org/releases/indigo
Hope this helps someone else too!
