Frankly, I would make your users add a more solid description of their discoveries - the current descriptions are very short...
As it is giving now a disorderly impression (sorry for my taste); must you could do this more neat way; it would be better.
Besides the couple things already said, I like the simple and clean design. I registered and submitted 2 articles, interface is good, easy to navigate. Nice site.
Being (somewhat at least) unique and nisched is more or less a requirement for websites these days; so how does your site differ from the other social bookmarking sites?