Y'all are lazy asses when it comes to inventions. If I could create invent anything I wanted, I'd make something that allows faster than light travel (for all intents and purposes, a teleporter). Exploring the universe would be pretty awesome. Instead of spending years calculating the probability that a planet can support life based on data obtained from a small amount of images and waves, let's just visit it! To me, the next MASSIVE paradigm shift after space colonization (like industrial revolution massive) will be faster than light travel. I'm assuming it's going to require some sort of manipulation of space-time (sort of like how turning a piece of paper into a tube would let you walk from one side to the other in an instant), but other than that I have no where near enough Physics to even realize how complicated even coming up with a theory on how something like this might work is.

The Ender's Game series (Ender's Game itself doesn't do too much) does a really impressive consideration of the implications of near-light speeds and instantaneous travel. It's also a fantastic series in general.

Beyond faster than light travel, I'd like to invent a few other things:

Flying Cars - Not planes with wheels, but real flying cars that can hover, fly through the sky, cruise along a street, etc.

A Working Lightsaber - Duh.

Something that Grants Immortality - Again, duh.

The Mother of all Swiss Army Knifes - Think like a wristband or watch that can morph into a gun, armor, a knife/dagger sort of thing (see: Edward Elric), a drill, basically whatever device you can think of. Maybe it'd make use of that liquid metal than can be solidified with an electronic current, except you could manipulate the current to cause it to take different forms. Hell, people could write apps you could download for different uses. It'd have to be pretty dense to expand that much, and I'd assume the ductility, Young's Modulus, etc. would be a function of density and current. Something that allowed for multiple basic structures (i.e. Face centered cubic, body center cubic, crazy pentagonal stuff, hexagonal, whatever you want) would be ideal.

Contact lens computers - Do I even have to explain how awesome this would be? Sitting on the bus, bored with nothing to do? Don't pull out your smartphone, just bring the computer in your contact lens out of sleep mode and start doing whatever the hell you want with complete privacy. The only issue is that this would be the ultimate form of distracted driving.

So there you have it. How much more awesome would it be to live in a universe with these inventions?