I have used the NOT gate for a very special capture ability. I used it so that the ability doesn't work if an enemy capship is in the area.
here is the diagram of the ability. I proudly declare it the most complex ability in sins.

To explain how the AND gate is usefull, let me explain what me and shadow refer to as a "Boomerang Buff"
A Boomerang buff, is a buff that starts on one entity, creates a second buff on a differnt entity, then creates a third buff back on the original entity.
You can see that it is a part of every diagram I have posted so far.
THe problem is, it is VERY difficult to insure that the third buff hits its intended target (the original entity)
In my capture buff above, I banked on the fact that in this particular mod, thier are only two players with one cap each. so the third buff in the Boomerang buff MUST land in the proper place. (In this case, it is the BuffRemoveTimer.entity)
However, most of the time, we can't garuntee that.
For example, One ability that we want to make will literaly TIE a particular module to a planet.
Whatever race owns the planet, will own the module. Plus, the ability to do this must be on the module.
Which means that we have to use a Boomerang buff. Which then means, that we have no way to insure that the Boomerang buff will target the original Module again. It it targets the wrong module, then THAT module will turn to the other players civilization, instead of the proper module.
SO, the answer is to include an "AND" gate. so that the third part of the Boomerang buff will only activate when it is on the right module.
We havn't made this ability yet. But we will shortly.
Again, as to a series of logic gates. I have no use for yet.
Key work: YET.