First announced in March 2012 but only now making its way into reviewers' hands, Korg's MicroKEY25 ($70) is the smallest keyboard in the company's lineup, and the only one that is officially compatible with iPads. Like other musical keyboards we've seen, this one doesn't connect directly to Apple's tablet but instead requires the USB adapter from the Camera Connection Kit. The MIDI controller works with apps such as Apple's GarageBand for recording…