Linux L2TP/IPSec with iPhone and Mac OS/X clients | PEEN.NET. Helped me install an L2TP/IPSec Gateway on my server that works with the iPhone. This is already a quite nice solution to not shout all data out loud at hotspots. However, due to the deactivated NAT transport in the Ubuntu package (due to security concerns), it is a bit fiddly because you really have to manually compile the strongswan package. Additionally, it's a bit annoying that you always have to manually activate the VPN on the iPhone - it doesn't stay active at the top. What you actually want with VPNs is for them to always be active - because otherwise you end up sending data accidentally over unencrypted and listenable paths.