Appart from those products, exists "stevia". This natural sweetener from Paraguay is always sorrounded of controversy and it´s said that it can promote insulin production, as well it can be mutagenic.
Much political controversy and decisions has been made about its use and production.
Here you can buy stevia at several stores related to natural foods.
I have tested a single leaf of stevia on my tongue and it was so sweet that hurts! Even minutes after the taste and discarding the leaf I been feeling the sweetness of it.
You can find some more info here:
Stevia - Wikipedia, the free encyclopedia