You need a Data Plan to use most services on a blackberry.
The following requirements must be met to use BlackBerry App World:
A wireless service data plan that supports web browsing
A BlackBerry smartphone with a trackball or touch screen
BlackBerry Device Software version 4.2 or later (BlackBerry App World 1.1)
BlackBerry Device Software version 4.5 or later (BlackBerry App World 2.0)