Amazon lets you flip through many of the books in their online store, while iTunes lets you listen to a preview of a song you're thinking of downloading. And soon, online grocery stores could let you sample their wares as well, thanks to this unique synthesizer that can simulate various tastes on your tongue.

Developed by researchers at the National University of Singapore, the simulator uses a silver electrode placed on the tongue that artificially stimulates the regions responsible for tasting sweet, sour, salty, and bitter flavors. By using a combination of varying electrical currents and subtly shifting the temperature of the electrode, a convincing recreation of various flavors can be experienced.

So much so that the researchers are working on a spin-off product that works like a digital lollipop, providing a hit of sweet without the downsides associated to consuming sugar. It will work kind of like one of those e-cigarettes, but providing chocoholics with the sweet satisfaction they crave instead of giving smokers a hit of nicotine. [New Scientist]