Not just for BlackBerrys either. I've used it on my Windows Mobile phone just by sending a text message (SMS) to that email address. Its usually bounced back in less than a minute. So it should work for any phone just by sending it as a text message.

It could be helpful when traveling abroad and you'd rather not pay the high fees for international data roaming to access the mobile NWA site. Usually text messages are cheaper to send/receive when abroad. But that may just be my cell contract. Everyone's is likely a little different.