As you learned earlier in the chapter, WCF is the Microsoft standard for web services. WCF services are extremely flexible, and you can use them in all manner of situations, from the most basic request and response to the most complicated secure services. In this section, you'll use WCF services at their simplest, with most of the configuration using the default settings.
Entire books are devoted to WCF services and their usage, and this isn't the place to go into details. In this section, you'll get a glimpse of how powerful even the simplest WCF services can be and how easily they can be put together. You'll also see how to implement REST services with WCF.
You can't create WCF services in Microsoft Visual Studio Express 2010 for Windows Phone (VSE for WP). Instead, you must have either the full version of Visual Studio or Microsoft Visual Web Developer 2010 Express (VWD). The advantage of the latter is that, like VSE for WP, it is completely free. You can download it from www.microsoft.com/express/ if you don't already have it or the full version of Visual Studio.
WCF services must be hosted somewhere, such as on a web server. Don't panic, though. This doesn't mean you need to upload them anywhere when you're developing your applications (although obviously you do need to upload them if you release your code). For testing, you can use either a local web server installation or simply the built-in ASP.NET Development ...