Boston company CyPhy Works has just launched the commercial version of the Persistent Aerial Reconnaissance and Communications (PARC) drone, which can stay up in the air for however long you want it to. The military's been using it to monitor its compounds for quite a while now, but the $22 million the company raised in an investment round enabled it to manufacture the product for commercial release. PARC can fly up to 500 feet, and it never has to land thanks to a microfilament attached to it that can transmit both power and data.