There was a thread last year about Google Maps: Calling google maps from powerbuilder
The 'type ahead' as seen on Google's main search box uses AJAX. The equivalent in PowerBuilder would be to use a SharedObject. The main window would call a function after each character is typed passing the string. When the function in the background thread is done, it would call a function in the calling window passing back the results. That function would then update the dropdown.
