The latest neat convergence box is this external battery pack for the iPhones 1 and 2. Like other external batteries, the iPower Portable Power Station juices the battery of the iPhone from its own reserves. When the iPower’s battery charge falls below five percent, it stops feeding the iPhone. Why? Because of the other feature, an external speaker. Apparently, that last five percent is enough to keep the iPower’s speaker running for seven more hours.

It gets better. Although the iPower is only designed for use with the two iPhones, it could be pressed into service (we think) for the iPod Touch, which actually needs an external speaker. The sound all goes through the dock connector, so as long as you can squeeze the Touch into the case (which is expandable) you should be good to go. $44.

External battery pack and speaker for iPhone: [via] – [source]