I\'d like to have an unique identifier for a cell phone. Since there is not a particular way to find IMEI or IMSI on every mobile, I want to know if there are other ways to
If your target device has JSR82, you can use LocalDevice.getLocalDevice().getBluetoothAddress() -- that's unique.
You can use just time in millis if you don't need strong UID. Or you can get UUID implementation from J2SE and port it to J2ME. In this way UUID should be stored in RMS. One of the best way is to build server side and distribute app only via this service. When new user try to download app you can put into manifest and jad any UUID you want and use it in your app via MIDlet.getAppProperty( String uuidPropertyName );