EcPc

EcPc provides a small collection of command-line tools to launch, list, log in to, and terminate Amazon EC2 (spot) instances. It's deliberately a simple tool with few parameters for a user to tweak, designed for newcomers to cloud computing. One particular feature of EcPc is that a "meter" allows to you keep a check on the (approximate) cost of the instances you have running, since this is an issue many new users are particularly nervous about.

For more details see here.

EcPc figure