The iGo powerXtender is probably included in the top 10 solutions for “useful way charge other devices instantly”. The small and portable product only needs 2 AA batteries to provide more battery to your cellphone/mp3 player, which can be extended up to 28 hours.

The charger itself costs $16, but you must buy a power tip to connect to your device, that costs $13.

Fortunately, the iGo has power tips for numerous gadgets. Here are some examples: digital cameras by HP, GPS systems from TomTom, Nintendo gaming devices, notebooks by Acer, Nokia cellphones, and many more brands/models.

- Convenient for travel of emergency use
- Compact lightweight design