For a selection of short, concrete and graphical examples of SOA implementations ( sort of "SOA in 3 Minutes Flat" ), see the PHP SOA project homepage. The aim of the SOA PHP project is to create, as a community, an infrastructure that simplifies the development of PHP applications in a service oriented architecture environment (SOA). Perhaps significantly, the posting was authored by Graham Barber of IBM.
The link is http://www.osoa.org/display/PHP/SOA+PHP+Homepage?showChildren=false