A solar power rig strong enough for powering a laptop and a few other gadgets is useful whether you need it during emergencies or just want to save some power. You can build your own rig for around $100.
Instructables user Khaleel123 shows us a DIY solar power rig he built to charge laptops, tablets, phones and other gadgets that use less than 100 watts. He wanted the power available day or night. His build uses solar cells (obviously) plus a 10-amp charge controller, 12-volt car inverter, LCD Voltmeter, and a few other odds and ends. Check out the full build at Instructables.
Solar Panel Setup around $100 [Instructables]