Well if you have a laptop check this out it. This can save you from having to pay for electricity for you computer and you can use it on the go so if you travel you can power your laptop anywhere.
http://www.earthtechproducts.com/sol...r-charger.html
Another thing a lot of people need is light, however, if you just go to sleep early like me that isn't going to be that big of a deal. This flashlight can aid your eyes if you are going around at night and it will charge in the day.
http://www.bogolight.com/
If your lucky you can just get solar panels and put them on your roof but I understand that a lot of people are not land owners so ya. After studying solar energy for a few months these are some of the most interesting portal products available.