In need of a global positioning system? Consider the Proporta GPS receiver, that wirelessly links to Bluetooth enabled PDAs (personal digital assistants), smartphones or laptops. What sets this one apart from other GPS units is that it can be solar charged via the small panel on one side. The panels will even work with no-sun light sources, such as indoor lighting, so long as you can get the GPS to within, say, a foot (300mm) of task lighting. Or 6.5 feet (2m) if the interior ambient lighting is putting out a combined 120W. Not sure of weight, size or battery capacity, but price is about £70. Or you could try their other thermonuclear based gizmo: a solar charger (£40), for USB ported devices (five other tips also provided). The good news is that this solar chargercan select four voltages between 3 and 9v and will not over-charge appliances. The downside is that its 3.6 V, 1800mAh, Lithium-ion battery likes to eat 34 hours of sunlight before feeling full. Although Pocketnow recently reviewed this charger, and they seemed pretty happy with performance, particularly as they reckoned a full charge took only five hours.