I think Amazon said it best (http://www.amazon.com/gp/aws/sdk/main.html?p=APIReference/RESTRequestsArticle):

REST allows you to make calls to AWS by passing parameter keys and values in a URL (Uniform Resource Locator). AWS returns its response in XML (Extensible Markup Language) format. You can experiment with AWS requests and responses using nothing more than a Web browser that is capable of displaying XML documents. Simply enter the REST URL into the browser’s address bar, and the browser displays the raw XML response.

Can you test your SOAP service with nothing more than a web browser?

Meerkat RSS feed – the javascript flavour is very cool.
http://www.oreillynet.com/pub/a/rss/2000/05/09/meerkat_api.html

Awesome use of javascript bookmarklets to search for books from amazon in your local library.

http://weblog.infoworld.com/udell/stories/2002/12/11/librarylookup.html

Its not a DecelerationHelper its a Brake.

Credit to Dan North and Mike Roberts for the conversation about how to rename Helper/Manager type classes to something more concrete. What ability or thing would the application lose if the Helper was deleted?