Hi,
1-Firt part of your question
Nothing
.It's a way to say that your application is trusted.With some handset, have a trusted midlet prevent to have some dialog of connection.
2-Firt part of your question
It is easy to sign your midlet with WTK 2.2.
Go to the "Edit" menu et choose "Preference".Choose the onglet Security et choose trusted.It simulates only a trusted midlet.
PS:Your application into the phone must be trusted by a organism such as Twaste or Versign etc...
OULD NADIF