Seems pretty inane, but this is the kind of stuff one has to worry about when writing articles. Although sometimes I can leave that to the great tech editors I get to work with like Melanie Spiller. I have gotten very good at properly casing things like SqlNotification and DataSet. But [web services] was always an issue for me. So today I went onto the W3C site and found the following on this page:

"The World Wide Web is more and more used for application to application communication. The programmatic interfaces made available are referred to as Web services."

Okay, so I'm sticking with capital W and all lower case for the rest.