"The process of tying two items together is the important thing," wrote Vannevar Bush in a seminal essay titled "As We Think," published in The Atlantic Monthly in 1945. Bush described a hypothetical device that would allow the storage and retrieval of data, the memory of mankind. It would be constructed of associative "trails," which future generations could consult and further enhance with new information. He called it "memex.

For many, Bush was a trailblazer of not only the PC but also the Internet. Almost 20 years later another visionary named Ted Nelson introduced the concept of hypertext, which would be integrated into his grand Xanadu project. Although neither Bush nor Nelson ever produced any actual solutions, they wrote the Rosetta Stones for integrated electronic data systems, and their legacies reverberate on the Web.

Last month, we could hear some temblors at a Silicon startup company called Third Voice when it unveiled something akin to Web Post-Its. Unlike real-world Post-Its, those invaluable little visual reminders and annotations, the cyber-equivalent is largely intended for the public forum. Heretofore on the Net, if you had something to say, you voiced your views in a newsgroup, a mailing list or, if you had the time, on your own Web page. Likewise, many sites have invited visitors to participate in discussions related to their content, but Third Voice takes this a step further, by allowing users to post on top of any document.