The successful government attempts were generally done use a ring of propellers or jets and gyrostablization(the same thing that keeps a segway from falling over). But due to manuverablity and speed issues they have been thus far impractical.
The successful hobbyist saucers use the Ion Wind to propel themselves and thus have to be very light weight(can't carry a human) and thus also impractical.
The eventual goal of either would be a solid state flying craft(no moving parts) preferably silent as well. This is not yet currently possible as scientists don't currently know how to create, destroy, or otherwise modify gravity. What they do know(proven by Einstein) is that gravity can bend space. That fact is what "gravity/warp" propulsion is based on. That would be shrinking the distance between your self and something in front of it and then moving toward it. The more you shrink the distance(the greater the warp factor for Trekkies) the faster the object would perceptively move. Impulse(AKA Ion) drives are currently used by NASA for deep space probs. These consist of a solar panel and a rear facing ion drive.
I've personally done through research on this subject in high school and built an ion wind generator capable of lifting itself-power supply for a science project then. My highschool physics teacher still has it.
P.S. As far as gravity goes. Scientists at the US's to largest particle accelerators are currently looking for the graviton particle to prove it's existence. Probabilty says they'll prove/disprove it by '07 or sooner. If they prove it they can beging to find ways to effect it and move one objects mass to another thereby increasing one gravity and decreasing the other one.
Breaking Stuff=Fun!,Bug Testing<>Fun!, Bug Testing=Breaking Stuff, so...
Bug Testing=Fun! Hmmmm....
DOES NOT COMPUTE! SYSTEM MALFUNTION!