In science fiction, traveling to other star systems is easy (not to other galaxies but to other stars). All you need is some super drive and poof, you're there. It seems that just about anybody, even a poor smuggler, can afford to buy and operate an interstellar spacecraft. (Yes, I like Firefly.)

In science reality, no human has flown over about 300 miles high in almost 33 years. We've sent unmanned probes to the boundary of our solar system. However, it has taken them almost 30 years after launch to get there. At the current velocity, it'll take the Voyagers over 40,000 years (going from memory, it's probably WELL OVER 40,000 years) to make it as far as the nearest star system.

Earth escape velocity is roughly 25,000 MPH. If you're willing to launch a small payload on a big rocket, you can go quite a bit faster (that's what the Pluto probe will do). With gravity assist, you might be able to reach 100,000 MPH, perhaps even more. Suppose, through some combination of nuclear energy driving ion or plasma thrusters over a period of years, you could eventually reach 250,000 MPH (10 times escape velocity). At that speed, it'd still take over 2,600 years to go a single light year - less than 1/4th the distance to the nearest star to our sun.

Perhaps science fiction makes it look too easy. We simply lack the technology to go much faster than what we currently achieve and it seems people are impatient to develop it. It's like a proud parent expecting his toddler to go from his first step to winning the Olympic marathon in a week. Some things just take time and hard work to achieve and you can't skip the intermediate stuff, no matter how hard and/or mundane it may seem.