What do you use for a backup solution to your phones?

Phones IMHO should be treated as disposable devices. You don't rely on them for infrastructure, you don't rely on them to store data that you don't already have another copy of elsewhere.

Build a robust network with primary / backup Internet and rely on that exclusively, don't expect to ever have to bring a phone into it. There are dedicated routers and modems that can connect to a 3G Internet connection which can act as your backup Internet connection if you want to leverage that technology. For example, the Draytek 2820 (http://www.draytek.co.uk/products/legacy/vigor-2820) and I'm sure there are many others.

If for some reason both Internet links go down, your network has failed you and you will have downtime. An individual user could use their phone and turn on WiFi Hotspot, and connect to their own personal Internet connection via a laptop. But this is a convenience measure for a single user who will treat the situation as if they are out of the office until the network issue is resolved. Cellular data on a phone is not suitable for a whole network to rely on.

As far as the actual data on a phone is concerned... again treat the phone as a disposable, volatile device. There should never be any organizational data on the phone that doesn't exist somewhere else. Email/calendar/contacts/notes/tasks should all be synced to the phone from a mailserver (e.g. Exchange, Google Apps, Gmail, Hotmail). Music should be a copy that is synced to the phone and the originals are stored on a computer or a cloud music provider like iTunes. Pictures should be regularly synced to the computer (e.g. using iCloud, USB sync, a third party app or something else) and the copy on the computer should be considered authoritative, the phone's storage is merely a temporary staging area where the pictures are stored prior to being saved to their final destination. Everything else on the phone is just settings and configuration which can be easily recreated later, so if a phone is ever lost, stolen, damaged etc. you just get a new phone, add your new accounts, configure it as you like, and continue on your way. If the user is seriously concerned about the downtime, then either they or the organization should have spares available (maybe an old phone, or spares from previous employees).

There are alternative ways of dealing with this situation of course and there are ways to backup a phone. iTunes lets you make backups of your iPhone which you can restore at a later date that will include all of your settings and data. Android also has similar apps and tools available, too. But IMHO these tools should be regarded as convenience tasks performed optionally by the user. Organizational policy should be that no truly important data should be on the phone and that losing a phone should be at worst a minor inconvenience.

Frosty,
I am looking at a redundant solution to office phones, i like the idea of using a Wi-Fi hotsport, but i think that would likely fail with 50+ phones connected to it. I have been looking at the idea of putting a redundant IPS up in our Co-lo and using a VPN connection with a dedicated pipe to that location for a fail over, but in the event that the world drops in the office,i am not sure that would help. Do you think a VPN connected to a 4G wifi hotspot could handle VPN traffic from an offsite IPS?

Currently we use digital and VOIP.

Thoughts?

Frosty, Thanks for the info..
I will take that and build upon it..