1. Create the payment rule that states if the amount is > 0, bypass (PayPal...)
Note: If you stop here, an order will be created, but no account will be set up and notifications won't be sent out for new users.
2. Leave the "Example Payment" type active, and add the rule that if the amount is = 0 it uses this process. Then edit the file at
/commerce/modules/payment/modules/commerce_payment_example.module to read something other than "Example Payment". I made my display
'title' => t('Payment Filter'),
'description' => t('Your invoice has a zero balance and thereis no payment due. To filter out spam please enter in any words in the space below"