On a recent trip, I ran into someone with an iPhone who told me something that baffled me. He said that soon after he got his iPhone, he sold his computer because he didn't need it anymore. Now, I love smart phones (I had a BlackBerry and loved it, and now I have an iPhone and love it), but it could never replace my main computer--I think.
For people like you and me, the reasons are obvious why this is so. For instance, we don't just use our computers for web browsing and email. We write documents, develop applications, and just build things in general. Some manipulate spreadsheets, and put together slides for presentations. Here it's clear; you require more than a smart phone.
But what about those who don't do any of these activities? These people have no need to edit spreadsheets, documents, or slides. However, what about downloading pictures from a camera, uploading pictures to a shared site, or downloading music? Well, you can do all of that from an iPhone, and you don't even need a separate camera. Ok, what about movies? iPhone's got that covered. In fact, you can text/IM, manage to-do lists, appointments, contacts, even write notes to yourself with an iPhone, never mind email and web browsing. Oh yeah, there are the hundreds of third-party applications that it can run also!
Therefore, unless you're actively authoring content (be it code, the written word, music, photo or movie editing, presentations, or numeric spreadsheets), or balancing a checkbook, you just may not need a computer that sits on a desk. Wait, the checkbook can be managed via your bank's online portal, and iPhone can handle that also - remove that one from the list ;-)
Still, I couldn't live without a computer in the classic sense. However, come to think of it, I really don't use a computer in the classic sense anymore - a desktop computer. I live on my MacBook Pro. Therefore, I suppose I'm a step closer to one day moving 100% to my handheld computer / smart phone after all. In fact, I have two wonderful 17" LCD monitors that I rarely use anymore because I almost never start the desktop computer they're connected to.
What about you? Can you live with your smart phone only? What activities can you absolutely not perform on your smart phone, besides the content creation activities I've already listed? Can you see the day when you're entire computing experience exists on a device that fits into your pocket? What would it take for you to abandon your desktop/laptop, and embrace your smart phone/device as the only computer you use? Write back and share with your fellow developers.