QUOTE(Alpha Weapon @ Feb 17 2006, 11:19 PM)
Hm, sometimes I can taste what I smell... I think its natural, though, as the two senses are so very similar.
Your nasal passage is connected to your throat, where your tongue is housed. The fact that smells are just particles of whatever it is your smelling make it almost as if your eating, except for the fact their so small you'd need to smell one for a few days to get a bite of steak. Yes, that goes for feces too.

QUOTE
To 1 in 500,000 of us, senses become unusually associated in a little-understood condition called synesthesia. A sensation involving one sense is perceived in terms of another, so that, most commonly, visions take on characteristic smells or sounds are associated with particular colors. Although synesthetic people are unlikely to share the same associations, they do share some aspects of their talents--their particular quirks are involuntary, remain constant over their lifetimes (a certain name or song is always a certain color), and they are absolutely convinced that what they perceive is reality, not something in their mind's eye.
We do not know what causes synesthesia, although it does seem to be inherited. The condition has been sheepishly reported to psychologists and physicians for at least 200 years. Various theories (all unproven) have attributed the condition to an immature nervous system that cannot sort out sensory stimuli; altered brain circuitry; and simply an exaggerated use of metaphor--taking such descriptions as a sharp flavor, warm color, and sweet person too literally.
In 1980, measurements of cerebral blood flow linked synesthesia to a brain abnormality. A person who tasted in geometric shapes inhaled a harmless radioactive chemical, xenon-133, which her tissues absorbed. The rate at which the chemical left certain parts of her brain indicated how metabolically active that part was. When brain activity was so assessed during a synesthetic experience, it was found that blood flow in her left hemisphere, particularly in the temporal lobe, plummeted 18% -- a decrease seen only when tissue dies as a result of a stroke. But the woman was perfectly healthy. The left hemisphere is the site of the language center. Another clue is that people with temporal lobe epilepsy are often synesthetic. Researchers believe that synesthesia reflects a breakdown in the translation of a perception into language -- but we have much to learn about this fascinating mixing of the senses.