http://www.arxiv.org/ Description from the site:
"arXiv is an e-print service in the fields of physics, mathematics, non-linear science, computer science, and quantitative biology. The contents of arXiv conform to Cornell University academic standards. arXiv is owned, operated and funded by Cornell University, a private not-for-profit educational institution. arXiv is also partially funded by the National Science Foundation. "
abd, ps, pdf, and other formats available.
I could spend days here.
Sorry, I didn't know which subject heading this should have been submitted under.