From the Zypad to iKey the present tech is rapidly catching up to the futuristic tech seen in video games. The US army hope to have this on the wrists of soldiers in the near future, and with hope this will help out boys so much that we start seeing the State side. If anyone has played the newest generation of "Megaman" then you know what we could one day see, I know I wouldn't mind having a BOS AI giving me status updates from my wrist!!
While this isn't a wrist computer it is still something that you could try to pass off as one if you really wanted to. Today's technology is advancing at a exponential rate and it's not hard to think about cellphones becoming outdated soon to be replaced with wrist computer's that have a built in wireless headset, or dental implant phones which work with said pip-boy wrist computer.