BusinessWeek’s reasoning, in a nutshell:

There’s too much spam, so good email gets ignored. Ergo, email is a lousy tool for collaboration. We should replace it with wikis… or something.

It’s true that wikis are better for “real-time virtual workspaces.” But that would be the case with or without spam. Why? Because wikis were designed for group-editing of documents… email wasn’t. Email was designed as an open standard for asynchronously sending and receiving read-only messages, and it still does its job pretty darned well. You can email virtually anyone in the world with near-certainty that they’ll get it and be able to read it.

Plus, anyone who’s opened a world-editable wiki knows that spam isn’t limited to email.

The BusinessWeek argument turns on what, exactly, is meant by “collaboration.” As a public service, Email Battles has compiled a handy table to help you decide which “collaboration” tool is called for under your current circumstances:

You need to… Suggested Tool
… call 911. Telephone
… air your political grievances to all the world. Weblog
… send your 96-year-old grandmother a birthday card. Postal Mail
… collaboratively edit your product’s manual. Wiki
… stay up-to-date with your favorite news site. RSS
… bother your best friend at work in real-time. IM
… bother your best friend at work asynchronously. Email

Print this page, and keep it on your nightstand. That way, when the smoke alarm starts screeching at 3AM, you’ll remember not to email 911.

See for yourself at BusinessWeek.