If all things go to plan I have a tentative trip coming up in a couple weeks. I'll be in some remote, unpopulated parts of the country. Even though I'll be accompanied by another Rover for most of the trip I thought it prudent to have the ability to jump start my vehicle without the help of another. I learned about the Antigravity Batteries on an offroad magazine I read in the newsstand.
After reading some good reports on offroad forums I decided to pick one up. I've had the battery die on me before on a trip in Utah. Luckily there was one other camper (the only other camper) in our campsite who was just about to leave that we were able to get a jump from. Ever since then I have always had cautious. Antigravity makes two models, I purchased the XP-1 which allows me not only to jump my auto but power my technology as well such as a laptop, iphone, Contour, or any other device that uses a USB port.
In addition to being a power source the battery also has a flashlight with a strobe SOS beacon function. The unit small enough to fit in your back pocket. So it will take little room in your vehicle. According to the manufacturer the battery can jump start V8 15 times in a row and 30 times for small engines.
The unit comes with a case to hold the battery, jumper cables, wall charger, car charger, cell phone chargers, and adapters. Retail is $159.99 but if you look hard enough you can get this unit for little over $100. Like a tire repair kit, first aid kit or even a pistol I believe it's a necessary addition to anyone who takes roads (or what pass for roads) less traveled.