Odata is a standard method to expose data through a WCF service. Typical services have GetThis() & GetThat() methods, Odata services expose Queriable interfaces that allow consumers to define data queries on the fly.
Odata delivers data as standard, XML Atom. But reference an Odata service in a Windows Phone project, and that XML is abstracted away – you get simple objects instead. Yeah!
Note: This post is about consuming Odata. Perhaps I will create an Odata service post later. One interesting point: consuming Odata in a Windows Phone project is identical to the techniques in ANY Silverlight application.