Yes, I agree... I think the cigarette lighter to cigarette lighter jumper is a simpler solution to the 9V suggestion, but how much do you want to bet that Jim steps in and comes back with a spirited counter? LOL
JK
In any case, here's a link to where I bought mine. No affiliation. Description tells you how it works. Basically, you just connect one end to the cigarette lighter to the doner car and then one to your car. There's a light that tells you when it's ready to perform the jump start (usually a 5 minute wait) and then you can start your car. Good thing is that you don't have to carry jumper cables, you don't need to pop any car's hoods (some people may not want you to put jumper cables to their car's battery and possibly connect a cable the wrong way and mess up their car), you don't need to touch your battery either, and you don't have to carry around an extra 9V around and make sure it's fully charged for when you need it. I can't see any easier solution. Hope this helps.
http://cgi.ebay.com/ebaymotors/NEW-Auto-Jump-Starter-Uses-Cigarette-Lighter-Socket_W0QQcmdZViewItemQQcategoryZ63687QQihZ013QQi temZ230079066287QQrdZ1QQsspagenameZWDVW