Fusion is a potential way to go. Light speed may be someday reached, but we currently don't have the resources to move large objects at the speed of light. We can do it with small particles. An example would be the Stanford Linear Accelerator Center in Palo Alto, California. Operated by Stanford University for the U.S. Department of Energy, they study Photon Science, Particle and Particle Astrophysics.
Small summaries from their site:
Welcome to a world of ultra-small and ultra-fast, where molecules and atoms hum, vibrate, and change states and locations in quadrillionths of a second. SLAC's synchrotron-based research program produces outstanding photon science that cuts across many disciplines. The scope of discovery potential includes previously inaccessible structural dynamics in the chemical, biological and materials sciences, generating applications in medicine, electronics, biology, solid-state physics, nanotechnology, energy production, and perhaps in fields yet to be discovered.
Particle & Particle Astrophysics:
Searching for answers to fundamental questions about the ultimate structure of matter and the forces between these fundamental particles, scientists use accelerators which speed electrons and anti-electrons to nearly the speed of light, and study their collisions and collisions from fixed target experiments. Using similar technology in astrophysics, space-based detectors will help us understand the birth and evolution of the universe.