Instapaper, Pocket (formerly known as Read It Later), and Readability are all great ways to "read later", or time-shift the Web articles and other content you don't have time to read now. (Think of them as TiVo for the web.) Some are highly focused on text, others also prioritize photos and videos. Some are highly focused on iPhone, iPod touch, and iPad only, others offer more cross-platform and Android support. Each one tries to solve the same problem -- letting you enjoy the content you want to enjoy, when you want to enjoy it -- but goes about it in a different way. So which one does it best, and for whom?
