If your bowl isn't too full, you can take a large bucket of water, hot or cold, and hold it high over the toilet and pour it real fast into the bowl.
I forget what this process is called, (hydro-something or other), but the weight of the water and gravity force the obstruction to flush on through.
You may need to try it a few times before it finally works.
Edit:
I guess I need to refresh more. 