I've been reading about the SOAP vs. REST-debate for years now and most of it seems quite pointless to me: there are clear cases where SOAP is useful and others where REST is preferable. In fact, I've had this experience recently when writing a tool that aggregated results using the several Websearch APIs. Yahoo! has a REST API and Google a SOAP API. To get results from Google, you basically run wsdl.exe on their GoogleSearch.wsdl-file and before you know it (approximately three lines of code) you've got a reference to a handy array of ResultElement-objects that store all the info you would ever want to have about a searchresult (or well, that they'll give you anyway).
In a post discussing the upcoming MSN Spaces API, Dare Obasanjo writes:
Wally mentions that Yahoo! has released an SDK to interface with several of their search engines using (what else?) webservices. According to the documentation, Yahoo! will allow 5,000 queries per 24 hours for everything except Local Search, which is limited to 1,000 per 24 hours. This is substantially more than Google's 1,000 for regular search.