
First off is the Juice Pack (pictured above). This buxom battery bolsterer boasts up to 350 additional hours of standby, 6 more hours of 3G talk time (12 for 2G), or 6 more hours of browsing. The design is of the ‘sled’ variety, wherewith you slide your iPhone into a shell that contains the additional power supply. Points for getting the job done, but aesthetics take a hit here and that’ll have to be something you consider along with the $99 price tag.
In contrast we have the Incase Power
Slider (pictured below). With 330 additional hours of standby, 5 hours more of 3G (10 hours 2G),
or 5 hours more online, the Power Slider is slightly inferior in the battery
boosting department. However, in a quid pro quo, what it lacks in battery life,
it makes up for in its visual appeal. The Power Slider has a more uniform
design, and appears much more naturalistic in contrast with the Juice Pack.

So it comes down, as life so often does, to looks versus power; beauty or brawn. Both make steps towards a more integrated power solution (over some other sloppy peripherals that dangle off the device like a vestigial appendage). But either way, you’re packing more pounds and additional inches onto your device.
The Juice Pack is already on the market,
and the Incase Power Slider debuts November 28th (pricing
forthcoming).