The Biefeld-Brown effect.

[s4nder]

This is an interesting effect where if a high voltage is applied between two electrodes, one small and sharp, the other large and smooth, the whole structure begins to levitate.

The interesting thing is that there currently isn't an undubious explanation as to what exactly causes the uplift. There are theories about ionic wind or the high voltage literally carrying air molecules but they haven't been confirmed.

http://en.wikipedia.org/wiki/Biefeld-Brown_effect

[Tanooki]

Mythbusters built one of these - but the myth was that it was "anti-gravity". It does produce a wind effect, but certainly doesn't interfere with gravity.

They tried it in a vacuum, and sure enough, it couldn't produce lift. (Episode ran December of 2006, so this is pretty old.)

[Darkflight]

Woooo. We lifted some tin foil.

They'll probably need a few decades to make anything really effective from that.

[s4nder]

Yeah, anti-gravity is a bit far fetched as anything that could completely bypass gravity would shoot off the Earth at over 250 km/s, and that's just considering the speed at which the solar system orbits the center of Milky Way.