This is an idea so simple that I am kicking myself for not thinking of it years ago: Distributing an ARES vCARD to members that contains contact information and the frequencies we might use during an incident.
Microsoft Outlook and Mac Mail support them, for sure, and I think Google Apps does, also. As far as I know, when you click on a vCARD pretty much any PC or Mac address book knows how to create a new entry containing the information.
Since many people now carry copies of their address books with them, this could be an excellent way to make sure they have your emergency information available. (I am wondering, however, whether all address books pickup the “notes” field from the vCARD. Please tell me how this works for you!)