Cases called Ampjackets claim to double the audio volume of the iPhone 5, iPad Mini, and iPod Touch without requiring any power.
Long-range acoustic devices (LRADs) are also called sonic cannons and can be used in wars and to repel pirates on the high seas.
PocketMail on Friday introduced a $99 e-mail device. The PocketMail Composer doubles as an organizer and an e-mail machine. It offers e-mail management applications, an address book and a calendar, the company said. PocketMail's service, which costs $14.95 per month, uses an 800 number to transfer e-mail. However, instead of plugging into a phone line, it is held against a phone receiver--similar in design to the acoustic coupler used on early modems--to transfer and receive e-mail. PocketMail is a start-up based in Sydney, Australia, and Santa Clara, Calif.