There is such a functionality built-in actually : when you upvote a story, it gets saved into a (private) list you can access. Check the "saved news" link in your user profile.
So upvoting stories serve two purposes : you help the community by making interesting and quality posts reach the front page, and as a side effect, you keep a track of them :)
Also, the "replies" link in the menu lists all the comments you posted, along with replies if it received any. In the former case, a little bubble is displayed with the number of unread replies.
Dual purposing UI actions leads to confusion in my experience. Even though well intentioned, the idea that voting also saves to a list is an unexpected result. Even for our savvy group, I would recommend using common user interface hints, like a star or a save for later element.
This replay was helpful, In fact I didn't know about this functionality. I also didn't realize the red arrows were to up/down vote. (this isn't very clear)
Perhaps make a "how to" page or something.
Also, I didn't notice "saved news", or how to use it with out your reply, perhaps move that to Top menu next to "replies" link or something.
I also agree with rsnickell about the saved list, favorites should be separated. It would be nice to star an article to read later, then if it's not very relevant anymore, remove the star to reduce clutter.
Echo JS is a great resource, I just think it has some easily fixable UX issues.
I like the way, how EchoJS is saving up voted news for reading them later and I also agree, that the UI/UX of voting/saving has to be improved.
Suggestion:
Instead of voting news, let users “star” respectively “unstar” them (like repositories on GitHub) and list starred news on the users profile.
What do you think?
Hmm.. I like the idea too of improving UX here. I think the voting is not too bad: https://github.com/antirez/lamernews/blob/master/public/js/app.js
What I think might be more helpful is adding 'tags' to a topic, such that you quickly can scan what topics are interesting to you, similar to SO.