wow, all this zealous work to keep the hard-drive platter from spinning up. why not just opt for an SSD if it's that important for you? Even the minimum of 128 GB should be plenty - if you have large media like movies, a tiny external hard-drive should be fine, and you're in charge of when it's connected.<p>[
As an aside, I think this is a really cool idea:
<a href="http://www.mcetech.com/optibay/" rel="nofollow">http://www.mcetech.com/optibay/</a>
How often do you really use that optical drive? (As people who use the mb air or 'ultrabooks' prove: not so often. And you can get an external one for when you really need one. Finally the optical drive is the first to break anyway, much easier to replace when exsternal). So you could have 128 GB ssd and 1 TB of large files there. When you really want to just use the battery as little as possible, don't access those files (you can probably even unmount it), and done.
]<p>BTW all this work to get to 10 hours kind of puts my following downvoted comment in perspective, doesn't it?<p><a href="http://news.ycombinator.com/item?id=3697907" rel="nofollow">http://news.ycombinator.com/item?id=3697907</a>