London-based BlackBerry Cool is, of course run out of the same city that was hit by a coordinated wave of terrorist bombings earlier today.

The site is reporting that in spite of a spike in London-area wireless, cell and Internet traffic today the only communication network that seemed to be working at capacity was the Mobitex technology's data-only BlackBerry service.

In the UK, the Mobitex service provider of record is Transcomm, which is owned by BT.

Transcomm sells the BlackBerry 5790, an early text-only model that few other carriers support. But on a day like today, the 5790 has had an opportunity to prove its continual relevance under fire.

The BlackBerry 5790, BlackBerry Cool believes, is "perfect for these sort of situations." Why? Because data-only networks, such as the one Mobitex runs, aren't filled beyond capacity with voice callers. Thus: data only devices for data only networks provides a type of connectivity unaffected by voice traffic logjams.