CERN 4th of April 2013:
We have now a phone bridge access number at CERN: CERN (CH): 71400 (from the outside +41227671400). Users are invited to use this numbers specially if they are sitting at CERN or Switzerland. The current number in Geneva will still be available and phased out at some point once the usage is completely migrated to this new access.
The full list of phone numbers can be accessed here: