It will be interesting to see if this actually works:
Article - WSJ.com Hybrid Satellite-Cell Pocket Phone May Arrive This Year - PC World
Hybrid cell/satellite phone. Uses cell system when in range, or satellite when not. Said to have 64K/sec data throughput, about 25 times faster than Iridium. It sure would be nice if it worked reliably, and was affordable. Coverage won't be worldwide, though -- only N. America and Caribbean, I think.