There (IMO) is a real need for a quality gift certificate system for wordpress. The process hinges heavily on form processing and it seems a logical fit for Gravity Forms. All the system would really need to do is to allow for the buyer to submit a form with either a dropdown price (amount) selection or a custom entered amount. Then send that amount to PayPal for payment. Once payment clears it would log the unique certificate number in the form submission (database) and send the buyer an email of their "gift certificate" which would have their unique cert number. The email could be really simple or a custom graphic. Once the buyer uses the cert, the store owner could mark the submission (within wordpress) as "redeemed" and done. There are a couple of plugins that do this, but they are pretty janky and incomplete. Love to see this functionality on Gravity Forms. :)