Watching a commercial for the iPad2 the other night, I thought, "Wow, that looks cool." And then, "Uh, what am I supposed to do with that thing?"
There are tablet personal computers, laptop computers, smart phones, ereader devices and a host of different operating systems and file formats. It's confusing. So before you drop a wad of cash on one of these things, let's try to sort it out.
If you want to read books, I'd suggest a dedicated reading device like a Diesel, iRiver, Kobo, Kindle, Nook, or Sony Reader. The smart ink technology makes reading for a long time much easier on the eyes than a computer screen. You don't have the flicker of the computer screen constantly refreshing, and it does make a difference.
However, if you want color for things like movies, games, video phone calls, and the Internet, a tablet pc with a touch screen may make more sense. If you have children, a tablet that plays movies and games may save your sanity on a long car trip. I have noticed that emails from friends who use tablets tend to be very short, so I guess typing on the touch screen isn't particularly efficient, but as long as you aren't using it for work, that may be okay.
And that brings us to work, which is still the realm of the laptop or desktop. If you really need to get work done, you need a mouse (not a finger pad), and a keyboard with actual keys (not a touch screen). I'm sure there are ways to integrate tablet computers into the workplace, but when you need to hammer out some long documents or write a program or even just clean out your mountain-sized email in-box, you need the tools a conventional computer supplies.
So don't let the brilliantly manipulative commercials steer you into buying something you don't need. Look at what you'll use the device for, and what you anticipate you might use it for in the future, and then think about what device fits.
All-in-one is not always best. Sometimes a device that does one thing very well is better. For instance, your phone may have a camera, but when you want to shoot some serious photography, you go get a camera. In the same way, for readers, an ereader may be a lot more efficient than a tablet or laptop.
Pick what you need, and forget the rest.
(The picture is from: http://www.ancientmesopotamians.com. And yes, I did learn to write on clay tablets.)