Quick side-note to the Vannevar Bush "memex" post below:
Bush's writings inspired two (going on three) generations of computer scientists, many of whom were major figures in the development of the personal computer and the Internet.
Right now, Microsoft senior researcher Gordon Bell is in the process of implementing Bush's vision for the memex with a project called My Life Bits:
MyLifeBits Project - Microsoft BARC Media Presence Group
Here's a link to a presentation (PowerPoint format, inevitably, and a 22MB PowerPoint at that!) that he gave in June 2005 to SIGMOD (the Management of Data special interest group of the Association for Computing Machinery.)