Input a search term and have a bunch of independent data sources look it up and present a unified result. That is it? Would Palm OS qualify as prior art? I can't see why not.
You would click the magnifiying glass, enter a search and every app (built in or add on) that had registered a search hook would launch one at a time and contribute results to the screen segregated by app and you could click a result to launch the app on that record. Each app was free to decide what information should be made available to the search feature.