Star Trek tech No. 10: Friendly androids
Perhaps the single greatest challenge in all of the Trekverse is creating a sentient android like the Next Generation's Lieutenant Commander Data. Even in the 24th century there was only one of him (well, two if you count his emotionally unstable twin, Lore). Somewhat less precocious cybernetic bipeds have been around for more than a decade, starting with Honda's walking, dancing Asimo (pictured). The first generation of robotic helpers has already been deployed to provide companionship for the elderly and infirm, as well as perform tasks too dangerous for humans. Let's just hope nobody develops an emotion chip. That could turn ugly fast.