So lately I've seen searches in the analytics for a "Quantum Entanglement NIC." This isn't possible under current technology, but it gives me an excellent idea.
A Quantum Entanglement network interface card would be useful because it would be linked to another card, and the two cards would act as if physically touching, even if separated by miles, astronomical units, or even lightyears. Literally instantaneous and uninterceptable communication. If it had a slot for a RJ-45 or wireless connection on top of that, so much the better. If it didn't, well, there's enough add-on slots in the desktop computer's motherboard to have a traditional network interface card.
Anyway, my idea is that we have an internet tablet (think like an i-Pad), and it has a quantum entanglement NIC connection to your desktop computer. The tablet will not run its own software, but instead be a mobile peripheral to your desktop machine. It is a terminal that fits in your briefcase, backpack, or other carrying device. It probably doesn't fit into a pocket or purse, but they're working on those. You would have all the features of your desktop machine, like high speed internet, your data, games, and so on, in a portable and useful form. The only thing the tablet wouldn't do well is type, unless your brought some sort of keyboard attachment.
You could have one entanglement tablet per quantum NIC installed, up to as many expansion slots as your computer has. This further expands the usefulness of computers if they have multi-user operating systems installed, and most these days are, for security and remote access's sake. One computer could be shared by four or five people, who access it through their tablets.
If you're not prone to losing physical objects, this would be good for security, too. It is literally not possible to intercept a quantum entanglement. There is no signal to snoop. However, if you do lose the tablet, you've basically given your computer over to whoever takes it, at least until you shut it down and remove the entanglement card. That would be scary.
Now, the current obstacles to this are in entanglement itself. For all its promises, quantum entanglement is a very fragile phenomenon. Entangled particles are difficult to keep entangled. If you disturb them, the entanglement is lost. If you read or write to the connection, it typically breaks immediately after. We're not even sure that a permanent entanglement is possible in theory. We're not even sure if that instantaneous effect works over long distances, or if it's limited to the speed of light like everything else. The current world record for entangled particles brought them 16km apart before the connection was lost. If you want a NIC, it's going to have to read or write so much more than than 1 bit before failing.