I use a very simple homemade bottle filler. It consists of a picnic tap with about 3' of hose added downstream of the tap. This hose passes through a drilled stopper. Dead easy to make and dead easy to use.
The length of hose past the stopper is just less than the depth of the bottle so it fills from the bottom to minimize foaming. Also, I hold the stopper in place with light hand pressure, this further reduces foaming by maintaining pressure inside the bottle. When near full, remove the hose, and cap over the foam (just like the big boys do).
I use this just to draw off a liter or two into flip top bottles when I want to take some brew along to share. It works great for this.
If you really wanted to bottle from a keg, for sending to competition etc, then a more complex counter pressure filler might work out better.