In the past few weeks, I've informally polled colleagues and some customers about how they use e-mail. Although the poll is an admittedly small sample size of admittedly techie users, I am finding a trend that is worth commenting on: people are spending less and less time storing items in and navigating through intricately designed series of nested file folders.
I used to create a folder for every customer, then would agonize when, for example, someone sent me a message about two separate customer issues. I long ago ceased filing items from my Inbox into customer-specific or other folders in my Outlook -- when I want to find something, I search based on a few keywords or re-sort by author, subject, or date (depending on what I can remember about what I want to find). I have over 5,000 items in my Inbox, and using search, find things faster now than ever before (without having to declare "e-mail bankruptcy.").
I do the same thing on my desktop using Windows Desktop Search (soon to be upgraded to Vista), but I rarely store anything other than temporary files on my desktop. Nearly all of my work data sits on my Shared Documents" and "Personal Documents" repositories in our SharePoint site, both of which are very easily searched as well.
Of course, web search has been written about ad nauseum, but I can barely remember a time where a question such as "Where can I park if I'm having dinner at Carlo's in Allston tomorrow night?" couldn't readily be answered with a few of the right keywords and mouseclicks.
Other than a few highly engineering-centric organizations I've encountered, and others who stubbornly just won't let go of their familiar way of storing and organizing data in folders, I'm seeing more and more demand for rich search capabilities and less for ornate data taxonomies. At the risk of sounding "ageist," in my experience there is a high correlation between this affinity for search and the age of the user -- users in their 20s don't know a world without search engines that are their (in a memorable turn of phrase from a Google exec), "Command line to the world."
Man, I've really got to read, "Everything is Miscellaneous"...