It may not be interesting or new anymore but web services are very necessary considering all the mash-ups of different technologies these days. Web services have a huge presence on the web. Just look at all the viral marketing going on integrating with FaceBook, Twitter, etc. Interacting with others data would be very difficult to do without Web Services. They are very important part of the webs evolution and expansion.
This is in no way designed to poo poo web services, rather understand what is going on with it and find out if it really is the technology we should be employing for our current project.
There is no other technology unless your going to be connecting to a third-parties database or code/source directly. If you need to figure out the real-time shipping cost or products being ordered or someones friends on Face Book there is no other way. In the end you need to ask that question to the person who knows and that person is the API provided by the source of the data to make the request and get the response.
However, I wouldn't get concerned with building your own API. The primary issue is learning how to consume/use others.
Once you use some you will see the true power of them. For instance, most people identify people by their IP. However, all an IP gives you is a number. Now, using some viral marketing techniques coupled with the Facebook API its possible to get someones true identity or tie it to the IP. Kinda scary if you think about it. Just think about all the possible marketing capabilities of that alone. Morally wrong or abuse of technology I'm sure its already being done.