The Iridium phones are pretty big--think landline cordless phone handset--and often have an extensible antenna. Given the mania for thinner and thinner phones, this probably isn't going to fly.
The network access is also expensive--think $50+ per month, with a handful (literally, like...10) of text messages and voice minutes included, with ~$1 per extra minute/message. If you live and work in somewhere with a modicum of infrastructure, this also probably isn't worth it.
(FWIW: I think part of their initial pitch was to Important Executives who need to be in touch with the office 24/7, but that seems to have fallen by the wayside and it's increasingly targeted at people going/living/working in remote areas).
