I LOVE Stevia and have used it for a few years now. I use the Stevita brand and I get 16oz jars from here: 
Omni Supplements - quality vitamins, nutritional supplements and natural health products 
For those unfamiliar w/ Stevia: 
*Stevia Rebaudiana is an herb in the Chrysanthemum family
*It doesn't alter blood sugar 

*It is 200-300x sweeter than table sugar
*Doesn't damage teeth (like sugar)
*No calories