Ctdh, a BitNami community member, has generously provided us with a great tutorial on how to make persistent data in Amazon Machine Images :
" Many of the instances of Ubuntu on EC2 are not based on an EBS instance which means you cannot stop/start the service without loosing the data and you cannot create your own ami fresh from the instance. So here is How to create your own Ubuntu Desktop on an EBS based EC2:
Make sure the AWS security group has port 22 open for the IP address you are using locally.
Launch ami-b3c0ebc7 AWS EBS instance (from http://alestic.com) using default settings.
If you use Windows to connect to the Amazon cloud, you can use the PuTTY tool, set the Host to ubuntu@[use the public DNS] and set Connection/SSH/Auth/Private Key file to the mykey.ppk you created in http://bitnami.org/tutorials/amazon_machine_images
Set Connection/SSH/Tunnels Source port: 9000 and to Destination: localhost:5901
If you want to install the Ubuntu Desktop you can enter the following commands at the terminal prompt:
sudo apt-get update
sudo apt-get install ubuntu-desktop
sudo apt-get install vnc4server
Enter a password when prompted
You can then install tightvnc client on your local machine and open a connection to 127.0.0.1:9000 whilst the PuTTY ssh connection is still open.
When your vnc client connects, you will be presented with a terminal window in the desktop. Type the following command to start your gnome desktop:
nohup gnome-session &
Apparently NXserver is better, but I have not managed to install it yet.
Hope this helps someone. "