Ask HN: Best VPN Server for iPad/OS X/Ubuntu Server

I run my own VPS with Ubuntu Server 10.04 and would like to have my own VPN to secure my connections when I use public wifi connections on my iPad or MacBook Pro.

I've tried looking at PPTP (even the maintainers of the server don't recommend it), Strongswan (NAT Transport is disabled in the Ubuntu package because of security issues), OpenSwan (I couldn't get it to work, possibly due to a bug in the version in the Ubuntu repos), and OpenVPN (not supported by Apple products).

Any tips on what would be the easiest way to get a secure VPN working?