I've got four (4) PRS-350's. One is used for fanfiction, the other for regular fiction, and the other two for backup. Also have a Kobo Aura HD because hoping to use it as replacement to the PRS-350 but despite all the features (front-light, wifi, etc), I still like the PRS-350 much, much better.
Before I got e-ink, I used an iPhone 4 and a 4th gen iPod Touch (backup when the iPhone was charging) with Stanza. I also have several tablets for larger-format reading material (comics, magazines, etc). The LCD-based devices are what get used for night-time reading. That or when I'm feeling too lazy to connect the PRS-350 to the computer for syncing ebooks with Calibre.
Given how many devices that I switch between, I usually charge to 80-90% and then turn them off when not in use. That way, at least I'd always have something with a charge for when my current device runs out of battery.
