I've put up some drycoded stuff for Do Not Disturb functionality where you can enter in a message to be told to people who whisper to you while the DnD function is active. Used for BossFight replies etc when you don't want to have to worry about missing tells. Acts basically the same as the AFK secretary, and reports the messages back when you toggle the function off.
May or may not work =P I'm at work atm, so I can't test it.
Although, I appear to have been given the incorrect prefix, as I was told <GA26>. I'll change it to just <GA to catch it all, but you can still use the prefix filter to add it in, Just add in a comma separated list of all the prefixes you wish HeyFu to ignore.