I think that would be fantastic. I have envisioned that kind of thing often. Something like "autodidact.stackexchange.com" (which doesn't exist), for example. The best explanations could be voted up. For bigger topics, it would not be explanations you're voting on, but rather "learning roadmaps" -- a recommended set of materials in a recommended order that is designed to help one grok the topic.

For academic papers, perhaps people could vote on two dimensions: (1) papers you'd like to see explanations for, and (2) particular explanations that were effective for you.

And yes, I would read the hell out of it, and yes, if there were areas I could contribute, I would do so.

Learning roadmaps would be huge, especially for programming languages.

e.g. "I want to create an IRC client in XYZ language"

simple i/o -> client-server/sockets -> simple parsers -> simple client (it's been a long day, this example sucks)

I would find that interesting. Like others above have noted, a lot of papers are written for reviewers, and not with the intention of making it easy for non-experts in the field to understand the concepts involved. It would even be useful to be able to post questions/comments about the parts you don't get and have people direct you to relevant background reading.

Yes. Although the field of "academic papers" is significantly broader with a smaller user demographic than hip-hop, but if you could pull it off I would be an avid user.

I appreciate the quick feedback - I myself would love to use such a service. Just to clarify, I don't have the development experience to build this myself yet (I just switched to CSE from Finance this year) but if anyone else would be inclined to give it a shot, I'd love to help. Otherwise, free idea!

Working on something similar actually.

I'd love to hear more about it. If you'd be willing to talk a bit, shoot me an email (on profile).

Same here! Would love to share ideas about this with both of you!