In the old days, finding obscure algorithms and data structures meant keeping stacks of books and trade journals in the garage, visiting book stores and local universities to dig through mountains of books and badly written and copied research papers.
Even in the Bay Area where there are great bookstores and two large universities, it wasn't easy. Whenever I read about something neat like Linda or spiral hashing, I drove over to the Stanford math & CS library and spent hours going through papers. Finding the paper often mean having to read papers mentioned in the paper so it was a good way to waste a whole day in that dusty library.
Thanks the Net, all that is replaced by Google and excellent services like CiteSeer and NIST WebSpace. NIST Dictionary of Algorithms and Data Structures is useful too, although it's not as complete as I would like. Unfortunately, most of these services are not updating their stat pages as often as I would like. For example, this list of most-accessed documents at CiteSeer was last updated in June 2003.
I wish these valuable services had easy ways to donate (PayPal?) because I think they are absolutely essential to my work and I want them to improve and expand their services. For example, wouldn't it be great if documents at CiteSeer were Wiki pages? This way, corrections to errors in the papers and implementations can be shared.