MXNA web services have been around for a long time, but they won’t work everywhere. For instance, Flash Lite applications can’t use web services. And sometimes web services can be overkill for small amounts of information that you want to retrieve, parse, and render very quickly. The answer is the new MXNA Flash Services.
Flash Services are very much in alpha, but they seem mature enough to start playing around with. Rather than using XML, Flash Services return data as query strings, or application/x-www-form-urlencoded which means they work perfectly with the Flash loadVariables function, and with the LoadVars object. Flash Services are primarily intended for Flash Lite applications, but can be used by any client preferring a more streamlined data service.
Check out the Flash Services documentation for more information, and let me know if you have any questions or comments. And keep in mind that I will be making changes to the APIs based on feedback, so anything you build could get temporarily broken.