I wouldn't allow everyone on my board to have this available, but only those that contributes to the board a lot. When someone creates a thread, while they get their email notification, they will also get a MOBILE TXT Notification! Everyone these days have Unlimited Text Messaging.
As the Founder of my community, I would add a new line on my wireless account with unlimited text messaging. Using that number to send and receive text messages. Would this idea be possible?