[Viktor's] laptop needed a new battery; he had the trade off between carrying around a cheap but heavy sealed lead acid (SLA) battery, or buying an expensive but light Li-Ion battery. Figuring his old laptop was pretty heavy already, and having an unused SLA available, re-purposing it for his laptop wouldn’t be too much of a hassle. Using a boost converter he built out of a custom dip MAX668, he is able to output the necessary 5 amps required. An MC 34161 voltage monitor chip is planned for future revisions, but he’s currently running it just fine. Check out some of his other cool hacks on Karosium.

Related: MSI Wind extended battery

Crafting isn’t really our thing, but just last week we were planning on doing this project. Thanks to the how-to singularity: the longer we wait, the more likely someone else will do our dirty work. The instructions are this:

1. Cut a hole in a book.
2. Stick your phone in that book.
3. Let her open the book.

Wired’s write up has about 600 more words if you need clarification. The ebook on the screen is Cory Doctorow’s Little Brother, so expect to see this on BoingBoing… and again when it’s fan translated into Polish. [bre] made a similar hidden compartment book last Fall for Make’s PDFcast.

In all seriousness, we do enjoy the idea of carrying an innocuous little book around that could be doing some covert WiFi scanning, acting as a mobile accesspoint, or live streaming our location to friends. Unfortunately, since it’s an iPhone, most of this isn’t possible yet; you can’t even voice dial from your headset, while leaving the notebook in your pocket. This case also blurs what is considered rude. Most people would be annoyed if you started txting mid conversation, but people taking notes in Moleskines don’t get the same treatment.