Keith's 7 Aug note: In its 30 July press release listing all MSL media activities and opportunities, no mention is made by NASA that offsite media would be allowed ask questions during press briefings - other than the vague "Two-way question-and-answer capability will be available for some of the news briefings from participating NASA locations". Yesterday (Tuesday) a number of media asked questions by telephone. Yet no formal media advisory was sent out by NASA noting that this was an option and how/where to participate. So early yesterday afternoon I sent a request for dial-in/off-site procedures to multiple people at JPL PAO, SMD PAO, and HQ PAO. No one from PAO ever replied.
Keith's 8 Aug update: JPL PAO sent me dial-in information 14 minutes before the press briefing began. A minute after I got this email I also got a general email from JPL PAO to news media alerting us of a dial-in capability. This was the first such note they sent out. Several other space media colleagues had told me that they were unaware of the dial-in option - until they saw my note or got this email. Annoying - its not as if JPL PAO has never done this before.