When in the debugging perspective, you should have a 'Variables' view and 'Parameter Stack' view (usually in the right panel). It should list all variables in current scope (including globals like the $_POST and $_GET arrays). In either of these you should be able to see the full values being stored--you can even drill into arrays and objects.
You won't have these in the PHP perspective by default, but you can add them by going Window->Show View->Other and selecting them from the 'debug' folder.