Use Event Triggers or something similar on non-UI objects?

Is it possible to use Event Triggers or something else that does the same job (allowing me to detect events on a game object and call a function on another game object of my choice) on non UI game objects?

I want to do this because on Android, the unity 4.6 UI lags a lot, so I am trying to use an efficient way of making sprites be buttons but not using the UI. Prior to 4.6, I just attached a Button script to every button and called the right method on OnMouseDown, but I am wondering if i can do it a different quicker way.

Any help is greatly appreciated, thanks.