Updated the thunder-ec2 script to support starting and stopping of clusters.  This allows cluster state to persist between uses (at the small cost of paying for the EBS storage space you use).
Added an ssh port forwarding option, which is a convenient and secure alternative to opening a port and connecting to iPython over SSL.  Using ssh tunnels saves a trip to the ec2 security settings page, and works well as long as you are willing to remain logged into your cluster over ssh when you are using it.  Also added a setup-notebook-sshtunnel script that configures iPython notebook and thunder for use in this mode.