Also, for the security issues with public wifi -- Tunnelbear is a reliable, legit VPN that works on mobile devices (and also has the benefit of doing geoproxy, so if you want to stream BBC stuff you can, which is what I use it for). They offer 500MB of data a month free, so you can keep it around for times you're doing something on your phone that you don't want to risk on public wifi and turn it off once you're done. (This obviously only covers "sniffing data in transit" and not "someone on the same local network exploiting a vulnerability in the OS to root the device and get at data on the hard drive", but still.)