I really really love the concept of time travel. Howveer, I don't think it's possible in the way we think because our technology is so limited. A few things with cool time travel concepts: Video games: The Legend of Zelda (Ocarina of Time and Majora's Mask both have good time travel aspects) Animes: Steins;Gate (this anime is on netflix, go check it out if you like cool stories =D) TV Shows: Dr. Who (most people have heard of this but who cares)
Well nothing is impossible. But the chances of that actually happening is lower then the chance of being the victim of a shark attack.
Time Travel should never be invented. The consequences are too dire and too easy to trigger. Look at the Back to the Future trilogy. Time Travel could also end up in wrong hands, like in MIB 3. Time Travel is a concept that never should be brought to life.
The movies were only an example. It's to show how bad the consequences could be. If Time Travel were invented, then my beloved Van Halen may not even exist.