Amazon Simple Queque Service

The book I read to research this post was Amazon Simple Queque Service Developers Guide which is an excellent guide which I downloaded for free from kindle. Amazon SQS in a nutshell is a method of sending a message upto 64kb in length from one computer to another via their servers on the cloud. It saves building a complex network. It doesn't deliver messages by default 1st in 1st out but rather weights them according to length although that can be changed in the settings. There are 2 types of permissions or rather who can read a message there is simple API which is the sender and the recipient and then there is advanced API which is setting permissions for other people to read it. There is a fair usage policy which prevents you abusing the system for example using it as storage. It's compatible with other amazon products in particular Simple Storage Service, Simple DB Database & Cloudsearch. Your messages have a minimum lifetime of one day although that is configurable. Amazon also guarantees every message will be delivered at least once. I think it's quite a useful web service.