Batteriser

[#1]

Batteriser is a $2.50 gadget that extends disposable battery life by up to 800 percent
It’s essentially a voltage booster that sucks every last drop of useable energy from ostensibly spent batteries.
So, instead of using just 20 percent of all the power hidden inside of your Duracells and Energizers, Batteriser makes effective use of the remaining 80 percent.
Voltage boosters are nothing new, but Batteriser scales down the technology to the point where it can fit inside a stainless steel sleeve less than 0.1 mm thick.
The sleeves are thin enough to fit inside almost every battery compartment imaginable
http://www.macworld.com/article/2928997/batteriser-is-a-250-gadget-that-extends-disposable-battery-l...

[#2]

Good free publicity for him and his company possibly ?
We've been building things like this for years in the electronics community - if you Google "joule thief" you'll find lots of info

[#3]

The USP is in its thinness, as per the article.

[#4]

See this thread on getting the most out of a battery
Battery Vampire
http://community.plus.net/forum/index.php/topic,115657.0.html