I\'m planning to develop an app for the iPhone and that app would have to access a couple of SOAP services. While doing some basic checking in the iPhone SDK I was not able
I've historically rolled my own access at a low level (XML generation and parsing) to deal with the occasional need to do SOAP style requests from Objective-C. That said, there's a library available called SOAPClient (soapclient) that is open source (BSD licensed) and available on Google Code (mac-soapclient) that might be of interest.
I won't attest to it's abilities or effectiveness, as I've never used it or had to work with it's API's, but it is available and might provide a quick solution for you depending on your needs.
Apple had, at one time, a very broken utility called WS-MakeStubs. I don't think it's available on the iPhone, but you might also be interested in an open-source library intended to replace that - code generate out Objective-C for interacting with a SOAP client. Again, I haven't used it - but I've marked it down in my notes: wsdl2objc