Maybe a bit off topic, but readability, readable, instapaper, etc - weren't user-defined style sheets supposed to address at least some of the issues these services are addressing? I ask because it seems that sometimes we get decent tech ideas (the
idea behind CSS is good at least) but then we settle for half-baked implementations and don't pursue good user tooling. CSS specifically - no browsers have good ways of defining/saving/using custom stylesheets, yet this (IIRC) was a selling point of CSS back in the day. Had we had better browser support for this, we may have had a much different web than we do today.
As it is, people think it's really cool when there's those stupid 3 font size icons at the top of a page and they can 'resize' the page's fonts between 9, 11 and 13 point fonts (w00t!)