Rasmus Lerdorf - Buzzing the Yahoo! Search Web Services:

"I still much prefer the REST services out there. SOAP always reminds me of being stuck behind the guy in a hat driving a Lincoln Towncar. You eventually get to where you want to go, but the journey is painful. With REST you can just toss your query into your browser and have a look at the returned XML. SOAP starts to make more sense when the queries you are sending get more complex than just tossing a couple of keywords to a search service and setting a couple of flags. But don't even try to read the SOAP spec. If you managed to fight your way through that spec already, try the new WSDL 2.0 Draft Spec. This is the sort of stuff that makes my brain hurt."