We propose a set of optimization techniques, collectively called Wireless SOAP (WSOAP), to compress SOAP messages transmitted across a wireless link. The Name Space Equivalency technique rests on the observation that exact recovery of compressed messages is not required at the receiver; an equivalent form suffices. The WSDL Aware Encoding technique obtains further savings by utilizing knowledge of the underlying WSDL by means of an offline protocol we define. We summarize the design, implementation and performance of our Wireless SOAP prototype, and show that Wireless SOAP can reduce message sizes by 3x-12x compared to SOAP. Categories and Subject Descriptors C.2.2 Network Protocols: Applications, Algorithms, Protocol architecture. C.2.6 Internetworking: Standards General Terms: Applications, Networks, Services, Compression, Performance.