We did it back in the day, using text messages (see here for one example). Other people have tried it more recently with 3G. In general, it's not optimal, due to phone->plane interface issues, rapidly changing OS and phone hardware and general problems that come with using hardware that wasn't designed for the job.
Also, we never go beyond a mile or two in our work, so the usual short range RF is fine. But it's certainly an option for longer range. Might be better to use embedded electronics with a 3G radio/simcard module than an actual phone, but the idea can work.
Replies
Actually the rest of their website is also worth a glance: http://www.smartskies.com.au/
Andrew
Also, we never go beyond a mile or two in our work, so the usual short range RF is fine. But it's certainly an option for longer range. Might be better to use embedded electronics with a 3G radio/simcard module than an actual phone, but the idea can work.