What is everyone using for backup batteries, because I know there are a few of the Case type battery backups out there and I was considering Mophi
http://www.mophie.com/juice-pack-air-p/1059_jpa-ip3g-blk.htm
But I am looking to see what everyone is using if any?
http://www.mophie.com/juice-pack-air-p/1059_jpa-ip3g-blk.htm
But I am looking to see what everyone is using if any?