Cloud computing keeps getting more interesting every day. With the open source release of a framework called Scalr you can now have a fully redundant, self-curing and self-scaling hosting environment utilizing Amazon's EC2.
Scalr allows you to create server farms through a web-based interface using prebuilt AMI's for load balancers (pound or nginx), app servers (apache, others), databases (mysql master-slave, others), and a generic AMI to build on top of.
Scalr was developed by Intridea, who describe it thusly:
Scalr utilizes EC2 to provide a multi-tiered hosting environment with pre-built images for load balancers, database servers, and application servers. Designed with flexibility in mind, users can further customize each type of machine to use as nodes in their server farm or customize a generic base image for any number of purposes. The application monitors and maintains the server farm by reconfiguring the entire cluster when machines fail or when new machines are inserted. Additionally Scalr can be setup to replace failed machines and scale up and down based on user configured thresholds. The application provides a simple web-based interface for configuring and monitoring your server farms.