The world is moving towards cloud computing. Your hardware won't hold any of your data in the way it does now. Your data will all be backed up in a cloud application like Dropbox (which everyone should use, by the way). Tethering your device to your data will be your wireless connection, either from your home/office network, or from cell phone networks. Wifi, WiMax, Netbooks, even the iPad. These devices all point the way forward.
Now here's a subversive thought.
First, imagine you don't invest in the tethering infrastructure, so your signal speed sucks. It's a bit like our country is, suddenly, without running water. This is a scary thought, because for a country dependent on Foreign Direct Investment, having the necessary infrastructure is a must to attract that investment. Everyone recognizes extending broadband provision is a problem, as my colleague Dónal Palcic has recently shown.
Second, imagine you want to break these networks down, for your own reasons, whatever they might be. These networks are essentially radio signals, and radio can be jammed, or bounced to other places. We've known how to do that since World War 2. So by 2050, we might see graffitti in a different format: kids hacking into your network for the craic, writing their names on your desktop, killing your signal for the fun of it, or scooping out what little privacy remains in your life, just to see if they can.