Hold [Shift] and press 421 for more money.

 Here are two more or less usefull key combinations. Type them
 anywhere in the game.

 $@!         Gives you 10 million pennies. You can do this only five
             times. After that the Death Star will come in and
             attack your heaven or hell.
 SAMNMAX     Type it 3 times (all in CAPS!) for the secret BAD THING