The iPads on sale at the Han City Fashion and Accessories Plaza, one of Shanghai's biggest shanzhai markets, sure look real. Upon closer inspection, however, one notices subtle differences. First, there's the screen size — roughly 5 in. by 7 in., or a touch smaller than the real iPad. But that's forgivable, given the extras, including a USB port, built-in webcam and expandable memory slot — none of which Steve Jobs' tablets have. And the price? About $140 (after some hard bargaining in passable Chinese). According to Timothy James Brown, editor of shanzai.com, a website devoted to China's knockoff industry, there are about 30 different iPad copycats on the market now, from Cynovo's C7 tablet to the creatively named iPed from Orphan Electronics. And for these producers, competition breeds innovation — hence the added features. "Apple may say, 'Let's keep the webcam off the device until we get to the next iteration of the product,' " Brown says. "But the shanzhai [maker] doesn't have a vested interest to play the game that way."