We've rented one from an outfit in Fla. a couple of times. I'm pretty sure it was global:
We took one down the Escalante in UT 2 yrs ago May and it worked as promised. But don't sit under a cottonwood and expect it to see the satellites! Doh. They ship it to you 2nd day air and you do the same on the return. It ended up being like $75-100 for a week in the end. It does have free incoming text messages (17 characters or so) so you can receive those important All OK at Home or PHONE HOME messages without dialing up. We got 2 batteries and used only one in 5 days, chencking in every day or 2.$1.49/min to call when you need it.
I heard there was a place in Cherry Creek? that rented them, some travel store, but I'd rather let airborne do the driving.