One example (there are a bunch) is this: bore a tunnel through a mountain from the base to the peak (or near the peak). Run some type of rail system up the tunnel. Mount the launch vehicle on the rail car. Accelerate the rail car up the tunnel. Ensure that the tunnel is evacuated of atmosphere before the run (or at least to a weak vacuum.) As the rail car reaches the exit, open the door. Launch vehicle is already traveling at 1/2 mile per second. Separate from rail car and launch. Rail car commences deacceleration, rail(s) now dip down (like from the peak of a roller coaster) and the rail car returns to bottom of the mountain. Launch vehicle goes on up to orbit.
Sound wild? It isn't - just requires precision in timing. High initial cost - bore the tunnel, big vacuum pumps, lots of power, administration and maintenance infrastructure, etc. But once it is built - much lower cost to orbit, because instead of gaining the 1/2 mile per second from using tons of fuel and a disposable 1st stage, just - race up the tunnel.
Could it happen? No - because it would take several billion in investment, and require all kinds of government regulatory agency signoffs. (Imagine the effect on the local wildlife, pollution, etc. Heck - you couldn't build the shuttle facility today!)
I say no it couldn't happen, but in fact if a small group of billionares decided to do this instead of playing with the stock market - they could probably make it happen. I'm not holding my breath.