Wow. A light-year is approximately 6 trillion miles. So Alpha Centari is about 25 trillion miles away. If I took an airplane that flew at 550 mph, it would take me 25 trillion/550 = 45,859,077,818 hours or about 5.2 million years to fly there on a Boeing 747.
Hmmmmm... not counting all the peanuts and magazines I'd need to keep myself preoccupied.
Lets hope scientists can come up with something faster.