OOB customer communications (Re: Looking for Support Contact at Equifax)

We're experimenting with Twitter as a means to communicate anytime there are system-wide outages (in addition to regular maintenance notifications). Adoption is slow but I foresee growth once we really get the word out. Being a data and VoIP provider, certain events can effect both email and telephone communications, so having a truly OOB method of contact is potentially invaluable. It would be awesome if there was a service like twitter that wasn't down as often as it is. Anyone have a list of all xSPs using Twitter? Mike