PETZL - TIKKA 3 LED headlamp This headtorch from Petzl uses three diodes instead of a standard bulb to enable it to give out light for up to 150 hours.

The Tikka runs on three AAA batteries (included) and give out light which decrease through three levels as the battery depletes. The first level lasts for about 12 hours and give good light for walking.

When the battery decreses the second level will last for 24 hours and gives out enough light to put up a tent by. The final level lasts for 150 hours and gives out enough light for reading. After this you need to buy some new batteries!
An ideal light for travellers.