The KeyMouse\u2122 is a keyboard and a mouse. It allows users to operate the mouse without moving their hands out of typing position. No more moving your hand back and forth between the keyboard and mouse.
Let’s not get into the legality of this device. But if you have a need to listen in on conversations for whatever reason, the Spy Bug Audio Surveillance gadget pictured above should do the trick. About as small as a pack of matches, it accepts a SIM card, which means you can just call it anytime you want to eavesdrop. Better yet, you can set it so that anytime there’s a sound above 45dB within 10m, it calls you! $60