I'm interested in exploring a design space personal computing devices have abandoned in favor of huge batteries and the most power one can use and still last about a day for most people.
Rechargeable batteries used to be expensive and not that great, so many devices used replaceable batteries and so needed to last at least a couple weeks on a charge. The Psion 5mx, Palm Pilot, and Game Boy Color are some examples in this space.
The main devices I can think of that are still in this space are e-readers and standalone music players. The book readers pretty much all run Linux now (and in fact mostly Android), demonstrating that a Linux device can last a long time if it manages power well and has a low-power screen.
The big problem with e-readers from my perspective is that their screens are too limited. A memory LCD would give similar contrast and readability while being much faster to update.
Memory LCDs are unlikely to support color, but with high resolution I think a memory LCD would still represent a big improvement in usability. Of course, manufacturers don't add them because the primary purpose of these devices is reading e-books, and an e-ink display is always going to look better than a memory LCD side by side.
@seanl To be honest, I prefer e-ink. I agree it's limiting as far as a UI goes, but there's this weird throw back to traditional book design that I really appreciate when developing the interface for an e-book.
I'm a straight up design nerd, but I think it's a credit to e-ink that it is so limited because it forces book designers to think more about layout spacing and type rather than implementing cool features that a device gives you.
@bhtooefr I just discovered they even have a 4.4" one with VGA resolution. Unfortunately they only do 8 colors, though. I'd prefer something like the ACX705AKM-7, which is 240x160 with 512 colors with 47mW typical power draw.