Here's a useful table that compares desktop with mobile for WCF work.

Feature	Desktop WCF	Compact WCF
Bindings:
·         BasicHttpBinding	Yes	Yes
·         CustomBinding	Yes	Yes
·         WindowsMobileMailBinding	N/A	Yes
·         ExchangeWebServiceMailBinding	Yes, via NetCF install	Yes
Formatters:
·         SoapFormatter	Yes	Yes
·         BinaryFormatter	Yes	No
Encoders:
·         TextMessageEncoder	Yes	Yes
·         BinaryMessageEncodingBindingElement	Yes	No
·         MTOMEncoder	Yes	No
·         GzipEncoder	No	Sample available
Transports:
·         HttpTransportBindingElement	Yes	Yes
·         HttpsTransportBindingElement	Yes	Yes
·         MailTransportBindingElement	Yes, via NetCF install	Yes
·         MsmqTransportBindingElement	Yes	No
·         TcpTransportBindingElement	Yes	No
·
XmlDictionaryReader/Writer	Yes	Yes; stub around XmlTextReader/Writer
DataContractSerializer	Yes	No; but can be wire-compatible with DCS via XmlSerializer
Service proxy generation	Yes; via SvcUtil.exe	Yes; via NetCFSvcUtil.exe, not integrated into VS2008
·         Non-HTTP transports	Yes	No
·         Custom headers	Yes	No
WS-Addressing	Yes	Yes
WS-Security message level security
·         X.509	Yes	Yes
·         Username/password	Yes	No
WS-ReliableMessaging	Yes	No
Patterns
·         Service model	Yes	No
·         Message layer programming	Yes	Yes
o   Buffered messages	Yes	Yes
o   Streaming messages	Yes	No
·         Endpoint descriptions in .config files	Yes	No
Extensibility	Yes	Yes