I think these are both functional and stylish, aren't they?
The designer Tsung Chih-Hsien has improved the design of these disposable phone batteries, which are also environmentally friendly (the package is biodegradable). It is a pill that you can plug directly into your phone for extra battery life. There are three versions of it: 2 hours, 4 hours, and 6 hours. According the source "The product allows you to tear batteries off a strip when you need them, and return the empty batteries when you buy a new strip." Reads lovely to me. Now I just need to figure where to get it!
You can read more on the designer here.