There is a youngish Yahoo group about sound symbolism, a.k.a.
phonosemantics at
http://tech.groups.yahoo.com/group/soundsymbol/
There's an enormous bibliography on this topic at
http://humanum.arts.cuhk.edu.hk/~twkwan/Humboldt/magmus-bib.html
I always had a feeling that /i/ (as in "ski") was most suitable for
expressing small, light, airy things, and /o/ and /u/ were most
suitable for big, heavy, deep things. So if I were inventing affixes,
for example, I would make sure my diminutive contained /i/ and my
augmentative contained /u/. Do you feel the same way about /i/ and /u/?
