I just configured my phone (Motorola Droid) to be compatible with the Amahi VPN. It wasnt terribly hard, but the method I used requires root access. If you dont already have root, this might be a good reason to get it. If you dont want to root, then this may or may not be helpful.
(For whatever its worth, I am using a rooted MotoDroid with Bugless Beast 1.1, which uses the Android 2.1 base)
As cale250 points out, there was an app called Tunneldroid. However, TunnelDroid has since merged with another group of apps, OpenVPN Settings and OpenVPN Installer. Both can be found in the market. I started by installing TunnelDroid, but I believe that wasnt needed. TunnelDroid directed me to install OpenVPN Settings, which then prompted me to install OpenVPN Installer. Throughout the entire process you need to allow the applications root access as they request it. I would recommend using whatever "Remember this" or "Always allow" setting you may have.
Once you have OpenVPN Installer installed and have run it to install OpenVPN, then switch back over to OpenVPN Settings. At this point you will not be able to do anything, as you havent copied your configuration files. If you already have VPN set on a computer, simply copy those to your SD Card in a folder named "openvpn". If you dont have a VPN setup, go to the
Linux VPN Wiki Page and download the three files there. You will also need to create the myvpn.conf at the beginning of the wiki page. Once you have those files, you can copy them over to the "openvpn" folder on your SD card (if it doesnt exist, create it).
From there you should be able to go to the OpenVPN Settings app and connect to your Amahi VPN!
If you have any questions, feel free to send me a message or reply here. I will try to see if I can do it without root, but it may take a while for me to get around to it.