LSL feature: L$ transaction event (extension of money)

The idea is an event able to pick up on L$ transactions from and to an avatar. This is not currently possible in real-time and it's not really doable at all. It's possible to create a script that can read and parse the web overview, but this requires the username and password of the user. A possibility is to introduce an extension of money, or a new event.
Ofcourse the user has to allow this when an object starts to listen for it. Similar to the permission given when an object wants to be able to take money from the owners account.

This should be a HUD and (worn)object specified function.

suggestion code:

llTransactionListen(); //Starts listening. 

llRequestPermissions(llGetOwner(),PERMISSION_TRANSACTION); //Asks owner for permission

transaction(key id, integer amount){ //id represents the key for the object or avatar giving or receiving money
  if(amount < 0) {
      //money is taken from the account
  }
if(amount > 0) {
      //money is given to the account
  }
}