I was looking for a way to host a Windows application online and after weighing several options, I decided to try out Amazon's EC2 (Elastic Compute Cloud).  I thought it was a good way to meet my business need without much expense and also gave me an opportunity to set up and play with EC2.

Amazon allows you to host virtual servers in their regional datacenters. Amazon using their AMI (Amazon Machine Image) format allows the administrator to set up a standard image and then duplicate it for redundancy or to provide more local service.  The real power comes as you leverage more of their other services such as SimpleDB or S3 (Simple Storage Service). The Elastic part allows developers to scale up as needed to meet demand and then scale back when things cool off.

Amazon's EC2 infrastructure is based on the open-source Xen Project but his highly customized. You can use some of their built-in available templates as starter images or build one from scratch.  For licensing reasons, I used one of their canned Windows 2003 Server images with SQLExpress 2005. I would caution using public images as they can be easily set up with some sort of back door.  Use your own or one of Amazon's. Then do a thorough check to make sure everything seems copacetic. And of course...change your passwords.

Security-wise other than passwords to the account, you need a certificate in order to start or stop the instance or make any modifications to firewall rules that are external to the server.

I will have more on my views on this as I work through.  Please leave comments on your experiences with Amazon or any other cloud hosting provider.