Nobody needs to be told how to use the lounge chair. "Users" of any age, background, or degree of sophistication can immediately comprehend it: take it in, in almost all of its details, at a single glance. It is self-revealing to the point of transparency, and the same can be said of most domestic furniture: you lie on a bed, put books and DVDs and tchotchkes on shelves, laptops and flowers and dinner on tables. Did anyone ever have to tell you this?

The same cannot be said of the iPod - which, remember, is one of the best-thought-out and comparatively simple digital artifacts ever developed, demonstrating market-leading insight into users and what they want to do with the things they buy. Take off your power user hat, try to imagine life without the chops you've earned over the course of your involvement with these complex artifacts, and you'll see that to people encountering an iPod for the first time it's not obvious what it does, or how to get it to do that. It may not even be obvious how to turn the thing on.

You don't have to configure the chair, or set preferences. You needn't worry about compatible file formats. You can take it out of one room or house and drop it into another, and it still works exactly the same way as it did before, with no adjustment. It never reminds you that a new version of its firmware is available, and that certain of its features will not be available until you do choose to upgrade. As much as I love the iPod, none of this can be said for it.