SanDisk (NSDQ: SNDK), the maker of the Sansa line of MP3 players (a distant iPod competitor), has acquired MusicGremlin, a maker of technology to deliver music over Wi-Fi. Among its products: MP3 players that can access an online music store directly from any Wi-Fi hotspot, allowing users to get songs either through a subscription model or a la carte. It also touts technology that works with ...