Seemingly quite pared down from the company's Pure-Fi Anywhere 2, Logitech's new Rechargeable Speaker S315i ($100) comes with a wall power adapter, as well as an integrated rechargeable battery with the ability to run for 20 hours on energy-efficient mode, or 10 hours on normal mode. Rubberized volume buttons are mounted on the unit's back, as is a three-position power switch for Off, Power, and Efficient Power, and a rubberized compartment for auxiliary…