The iPhone works pretty well as a substitute voice recorder, but if you're looking for better audio quality while shooting video or doing interviews, you can now plug a boom mic into your smartphone. The 4-inch long device, imaginatively called the iPhone Boom Mic, plugs into your phone's headphone jack and is available now for $40. It includes a directional setting feature so that you can optimize recording based on how far away you are, and it won't be a drain on your iPhone's battery since it runs off of a single AAA battery. Despite its name, the mic is compatible with most iOS devices, including the iPod Touch and iPad — and while it might make a great companion to your tripod-mounted tablet, it's a shame it probably won't work with the multiple lens case.