I haven't tried it myself, but people say this works:

[quote:6d4985945c]As per MIDP specs - define a TextField of type PHONENUMBER. When the TexField is selected click the 'CALL' button on the phone. This initiates a phone call. MIDP specs also say this functionality may work based on the phone implementation. It works on the Samsung A500.
[/quote:6d4985945c]Or try this...
[code:1:6d4985945c]com.sprintpcs.util.System.setExitURI("tel:5555555555");
notifyDestroyed(); [/code:1:6d4985945c]