Basically you need to start the network request in a background thread.
Once the network operation is complete you should notify the main/UI thread to change the waiting screen into the results.
To notify the main thread have a look at the link below and search for invokeLater:
http://developers.sun.com/mobility/midp/articles/blackberrydev/
Word of advice: Don't spawn to many threads at once on mobile devices. Usually they have a really low maximum number of threads.
