The Pak-Lite 'Super' is a very simple and very lightweight flashlight (4 grams) and uses a PP3 9V battery (36 grams) and may be suited for PSK emergency kits, rather than EDC. Pricing is around $20 for the Pak-Lite 'Super'.
Size comparison to a Mini Maglite with Nite Ize LED conversion.
The feature which makes the Pak Lite quite outstanding is the run time life of the Pak-Lite quoted at nearly 80 Hours by the manufacturer on the highest setting and 1200 hours on the lowest setting when used in conjuction with the excellent performance of the Ultralife Lithium 9V PP3 Battery (has the ability to deliver an amazing 9 WHrs energy). I suspect that this might be somewhat exagerated though when looking at the discharge curves for the Ultralife.
http://www.ultralifebatteries.com/images/products/U9VLX/U9VL-J-X-BP-charts-lg.gifI measured the draw current at 37mA on the highest setting so I would expect the Pak-Lite to have a useful runtime life of around 35-40 hrs on the highest output setting. The highest output would be around 12-15 Lumen or around the same output as the Maglite with the Nite Ize LED conversion. (the Maglite has a useful run time of around 12 hrs with standard AA alkaline cells)
The lowest setting drew less than 2mA (less than 1-2 lumen) but was still useful to navigate around a completely darkened room when my eyes were night vision adjusted and to read text from a book or to read from a map.
The Pak-Lite also has an excellent form factor for storage in a rectangular PSK storage case and when it is used in conjuction with the excellent Ultralife Lithium battery has a very long usefull storage lifetime up to 20 years with a self discharge rate of 0.16% per Month. Lithium Cells will also work down to -40C temperatures as well.
The major downside is probably the lack of any waterproofness, although this can be solved by putting the Paklite into a small clear plastic zip lock bag if required.
So to summarise, the Pak-Lite 'Super' is extremely compact, is as bright as the MagLite with the Nite Ize LED conversion but will have the runtime nearly 3-4 times that of the Maglite. Overall there is probably nothing as compact with the same performance run time out there.
The Ultralife Lithium Cell may also have additional uses when used within a PSK. It could also be used as an expedient firelighter when used in conjuction with some fine steel wire wool tinder.