If you’ve been waiting for HP’s highly anticipated TouchPad tablet, the company just sweetened the deal a bit more for you. HP recently announced that anyone who purchases the 32GB TouchPad before July 31st will get a $50 mail-in rebate off of the purchase price. The catch? You’ll have to prove that you already own a Palm Pre, Pre Plus, Pixi, or Pixi Plus smartphone. The TouchPad offers a 9.7-inch display, NFC capabilities for unique interactions with HP webOS phones, and a 1.2GHz Qualcomm Snapdragon processor. It’s available in two capacities, 16GB ($499.99) and 32GB ($599.99). AT&T will offer a 3G version of the device later this summer, but pricing and an exact launch date have not been detailed.