A paper published in recent issue of the scientific journal Nature, describes a case of a woman who has the synaesthetic experience of tasting sounds and seeing them as specific colours.
She is a professional musician and uses her unique gift to pick out specific notes and tone intervals. Her abilities were tested by asking her to identity specific tone intervals while tasting sour, bitter, salty or sweet solutions.
When compared to other musicians, she found it more difficult when the taste of the solution differed to the taste usually produced by the tone interval, than when they matched.
Link to study summary from nature.com.
Link to writeup from wired.com
Mind Hacks 
On synaesthesia for colour and taste, it might be worth checking out this paper published very recently:
Ward, J., Simner, J. & Auyeung, V. (2005).A comparison of lexical-gustatory and grapheme-colour synaesthesia. Cognitive Neuropsychology, 22(1), 28-41.
Jamie Ward is familiar to both myself and Vaughan, as he is my PhD supervisor and ran the Masters course that Vaughan did. Viv Auyeung used to be taught by me when she was an undergraduate; she has since moved on to better things. Not that thats hard. We’re still friends, so it can’t have been all bad…
link for abstract here:
http://tinyurl.com/5ofn8
I’m so happy to have found this site! I’m a 13 year old girl who happens to have synaesthesia. (No, I’m not self tested. My parents kinda freaked out when I was like 4 and I was like your name is green ((I have grapheme –> color synaesthesia)) and also when I would say stuff like “your voice is purple”((I have sound–> color synaesthesia as well))so they took me to a pediatric neurologist.) Anyways, my friends are like “Awesome!! Am I one?? Where can I read about it??” and your site is one of the best I’ve found. If anyone is interested, another superr good site is synesthete.org. For more info on synaesthesia, feel free to email me at katie.givan@gmail.com!!
I have four different tyes of synesthesia, this is really cool, thanks! Im listening to ‘the fool on the hill’ by the beatles right now and its got lots of pretty colors and REALLY cool shapes. I see time a circle that is slightly to the left of me, with all months having their own colors, and all the words I am typing right now form a mis-arragned rainbow, as well as each letter having it’s own personality. Of course I’ve always thought this way, and so to think that others can live without thinking like this is pretty weird. I’m thirteen and female.