Your Mac is already great at Web surfing, but the ATI TV Wonder HD 650 lets it surf TV channels too. If you have a fast system, the USB TV tuner feeds fluid broadcasts from analog and digital over-the-air channels, cable TV, or another source. The device even buffers live TV and saves shows like a standalone digital video recorder. But even with a high-end computer, the included software sometimes disappoints—and it has a confusing interface. Plus, the tuner can bog down a midrange Mac, slowing down all other apps in order to keep the video smooth.