(Disclosure: I work for Google, but these are my personal opinions.)
Apps like Pocket and Instapaper are a boon, letting you save articles to read later. This comes in handy in many situations, such as when you’re at work, and want to save something to read at home. Or when you’re trying to do something, and want to tame distractions. Or when you’re already doing too many things, and don’t want to take on yet another task at the same time. Humans, after all, have a limited ability to multitask.
Or when you’d prefer to read an article on a different device. For example, if you come across an article on your phone, via Twitter or email or some other medium, you may want to save it to read later on a bigger and more comfortable screen. Or when you come across an article on your PC, but find the iPad to be a superior, distraction-free reading device.
Unfortunately, “read later” apps like Instapaper have been something of a hack. They really need to be integrated everywhere —into all Internet services, apps, browsers and OSs.
You can see the beginning of this into Tweetbot, which lets you save articles to Instapaper, without even opening them:
But this integration needs to go much further — not just Tweetbot, but all Twitter apps and the web app. And other social networks like Facebook, Google+, and LinkedIn.
And other online services such as Gmail:
Notice the Read Later button next to Archive. Clicking this button would save the current mail  to the Read Later app that you use, whether that's Pocket, Instapaper or Readability.
Another entry point would be the “Reply” drop-down menu for each mail in the thread, which could have a Read Later option in addition to Reply and Forward:
Support for reading later actually needs to be built in to browsers themselves. For example, when you right-click a link, you should get an option to Read Later in addition to just opening in a new tab. In retrospect, it seems that the idea of opening everything in a new tab is designed for a species that has an infinite multi-tasking capacity. Why do you have to or want to read everything right away? It makes no sense.
In addition to right-click menus, browsers should have a Read Later button on the toolbar. Not the bookmark bar, as with bookmarklets, since the bookmark bar is hidden by default.
Reading later should also be built into the in-app browsers that many iOS apps have (Android apps don’t use in-app browsers), and into OS X.
Let’s not assume that users are willing or able to read everything right now. Design for reading later, and integrate it into all platforms, Internet services, browsers and OSs, for a seamless user experience.
 Or perhaps thread. Let’s leave that aside for now.