Kino said:
...in a world with 24/7 communication, staff has to have a means of access to some sort of instant messaging service where if needed they can be contacted. Plus, I don't hesitate to give my cell number to folks sometimes if I'm needed for an emergency. Plus, most texting plans these days are free anyway. OR you can use any free instant messaging apps on iPhone/Droids as well.
There is no excuse for zero communication.
Of course there is...
If your "forum-employee" is at work, spending time with family or friends, out grocery shopping or at the theater watching a movie (for example) the internet can wait. That is valid enough for "zero communication" when they're away from the computer.
I know I wouldn't want my phone buzzing away and making noises when Im out & about over forum related stuff nor would I want forum-related Skype messages popping up evey time I log into my computer.