I brought my Zoleo along with me during Colorado 3rd season, but I ended up leaving it in the pack the entire trip because the iPhone functioned so well.
I found the best use for me was to leave the phone in airplane mode w/ battery saver on until I wanted to use it to communicate. Spend the 1-2 minutes connecting to a satellite and sending a message, while simultaneously receiving any messages that came in while the phone was in airplane mode. After I'm done sending messages, the phone went back on airplane mode. I noticed it would drop an average of 1 percent or less for each check- in. I tend to check in 3-4 times/day so the battery drain was minimal.
If you were in a group of guys using it to communicate on the mountain, I would say you could get away with a similar use, just set designated check-in times with each other so you aren't running around with your battery draining all day.
I really want to hear if anyone knows of a service that can send an updated forecast using your current location all through text-message. I know there is a share-location function built into the satellite messages, so I would assume this is possible hypothetically.