Science-fiction, or in this case, science-fantasy, often inspires real inventions. I find it pretty fascinating to watch this video of a new prosthetic the creators call the "Luke arm".
It probably doesn't come with a feature that allows for the hand to pop off, seeing how it might be irritating for the amputee to have someone (e.g., me) keep asking them to lose a limb for my own personal entertainment while I chop it off with my plastic lightsaber. Sometimes, no matter how geeky-cool an idea is, it's just plain wrong. Sigh.