Review about Hp TouchPad, this gadget was so impressive, why? because With all the attention lavished upon would-be tablet competitors to the Apple iPad, like the Motorola Xoom ($599, 3.5 stars) and the RIM BlackBerry PlayBook ($499, 3 stars), HP's webOS-based TouchPad has mostly flown under the radar. That should change rather quickly, though. HP, which has allegedly been designing the TouchPad since day one of its Palm acquisitionmore than a year ago, did something rare: The company waited until the product was ready to release it. The TouchPad is the antithesis of the PlayBook or the Xoom, which were both initially