The Web's fifteen minutes of fame ended about two years ago. Napster (and peer-to-peer applications in general) are currently leading the field in terms of technological sex-appeal.

Messaging systems (ICQ and the like) had a brief turn in the spotlight during the late 90s, but didn't have what it takes to be a true network explosion. Chat systems are synchronous systems (both people have to be online at the same time), and the real prize of using the internet is asynchrony.

Time-shifting is the true killer app of the internet.

Email, the Web, and peer-to-peer services like Napster let people communicate without forcing both parties to be on the same line at the same time. That only makes sense, because computers are nothing but glorified mechanisms for handling the single most valuable time-shifting technology ever invented: written language.

The Web is a communications breakthrough on a par with moveable type, but not because it makes passing information from one place to another fast. Speed is boring. The real breakthrough of the Web is that it's given rise to written languages for things like pictures and music.

The JPEG file formats, MP3 audio, MPEG and DVD video.. They're all forms of symbolic notation, just like text is a symbolic notation for speech. We haven't been able to use those forms of notation until now, though, because they're too complicated for humans. It takes something with the speed, accuracy, and and sheer patience of a computer to make those forms of notation useful.

It also takes a medium of communication, though.

Moveable type didn't come around until long after text was invented, but it made using text much easier and more valuable. The Web hasn't made JPEGs and MP3s come into existence, but it is making them easier to use, and thus more valuable.

This is the kind of thing geeks think about.