I disagree. To me email and IM are in he category of "time wasters". Well thought out emails are good. But short one-liners without much thought are more likely to be time wasters. And then the volume of corporate emails not tied directly to work are also time wasters. The time we waste to get a clean inbox should be counted.

I mean, both do have their uses. IM can be great for live debugging. But most IM's do not fall into that category.