My roommate showed me a packet of little tablets the other day. They're called Miracle Tablets, because they're made from a berry called the miracle berry. At first, I eyed them suspiciously, since the name "miracle berry" sounds like a drug.
Turns out they're not -- miracle berries are real berries, and these are just a tablet form. You can buy a packet of them for $15 at http://www.thinkgeek.com/caffeine/wacky-edibles/ab3f/
(no, I'm not an employee at thinkgeek or anything, that's just the only place I know of where you can buy these tablets. You can probably find 'em elsewhere.)
What are they? They alter your taste buds (very temporarily, about half an hour), making sour/bitter things taste very sweet. They work particularly well with sour/bitter fruit.
After taking a tablet, I ate straight lemons, limes and grapefruits... and they tasted like sugary lemonade, limeade and grapefruit juice. It felt like a sugar rush, even though I wasn't eating sugar at all! Unreal.
Basically, it's a great way to satisfy my sweet tooth while barely eating any calories at all!
The website DOES warn that having these tablets ALL THE TIME is a bad idea, because the acidity of lemons/limes/etc can harm your mouth, even if you can't TASTE the acidity. (Plus, they run about $1.50 per tablet, so it'd probably get expensive if you had them all the time.) HOWEVER, I've found them really handy when I'm REALLY craving something sweet.
Have you ever had (or heard of) these? What do you think about them?