Amazon Elastic Compute Cloud (Amazon EC2) is part of Amazon Web Services. It provides "resizable compute capacity in the cloud"---in other words, it allows you to run what are essentially virtual private servers of various sizes and capabilities. It is relatively straightforward to set up a WebObjects application server on an EC2 instance. There are several flavours of Linux available as base images to customize.
Amazon EC2 presentation from WOWODC 2009
You can get more information about Amazon EC2 in the presentation Ubermind made about it at WOWODC West 2009. Please note: WOLastic is no longer supported, and this document describes the preferred methodology.
Search your preferred region for just about any instance of Amazon Linux to find an appropriate server and configure your instance using instructions for Automated Deployment on Amazon EC2 Please add any AMI-IDs you validate as working with WO or choose from the following Public WO AMIs already listed as follows: