Well I guess you "could" use a JavaScript extension and KSOAP in java (On a BlackBerry smartphone) to call a web service... Typically I see this type of request from a developer who has a Java client background who is now coming to the Web.... Am I close 
I defininately would not recommend it.
There are much better and easier ways to call your web service using standard web technologies in your WebWorks application available on any BlackBerry device 5.0 and higher.
If you are coming from a mobile client Java application you will definately have a different way of thinking about tackling the problem. Most all web developers will aggregate this data via a server side script and then serve up the minimal needed data via JSON over a restful web service. Most Java developers will go straight to the SOAP web service with multiple requests to get their data to avoid a server side script.
SOAP web services are typically bulky, chatty and complicated requiring multiple web requests that do not work great on a wireless network that has issues with latency.
Take a look at my sticky post outlining some techniques for accessing a web service via JavaScrpt
