What do you think about a reputation based link access?
Post worthwile stuff = get worthwile stuff
Leeching isnt a bad thing but I am sure that there are people around who do have missing content but are too lazy to post it. Perhaps that could motivate them.
You have to be careful not to make it too difficult. Not everyone has anything unique to contribute and even when they do, people very rarely give out reputation. Even a mega contributor like you only has 39 rep.
I mean reputation maybe above 2, 3... this kind of levels. Just to motivate people to post whatever they have because we have almost a thousand users and I can't believe there is not a single person who doesnt have anything that wasnt posted here.