Another option for getting a mobile charge on the run

It's only when I'm at trade shows that I really notice how quickly my iPhone runs out of power, so I'm constantly on the lookout for chargers that can help out during the middle of a long conference day -- particularly charging options that don't necessarily require a power outlet.

Enter, another solar powered option that works with mobile phones, digital cameras and MP3 players. The Freeloader Solar Charger series, from Solar Technology International, will be available starting in May from various U.S. retailers.

The Freeloader PICO, which is priced at $29.99, takes 30 minutes to charge up a mobile phone or media player. It includes a 75mA solar panel. The standard edition Freeloader, which is about the size of a mobile phone, uses two 120mA solar cells. It can supply enough charge to keep your mobile phone running for up to 44 hours in standby. The suggested price is $59.99. The final product, the FreeLoader Pro can charge a broader array of devices from smartphones (including an iPhone or Blackberry), mobile gaming gadgets, MP3 players, GPS devices and electronic books. It comes with an accessory, called CamCaddy, that also lets you charge digital camera or video batteries. The device has a suggested retail price of $119.99.