I think a security wiki is n1 but as you see, there are allready some of them...
May a good article archive (tutorials about howto secure, howto worx some systems, howto hack a system (auso important to understand a mechanisme))... but else it's may just 'normal'
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r may a realy great link archive (with a good structure, any1 can submit links, but there 'll be checked by admins...)