I've only ever used the dry type, simply because I don't use sufficient to warrant keeping fresh around (the only herbs I normally use are coriander, parsley, mint, chives, rosemary, sage and thyme, most of which grow just outside the back door. I tried growing coriander there, but the snails and slugs were convinced I grew it solely for them, so by the morning there was none left). I use curry leaves in Bombay Aloo, Masala Dosa and so on. Dr Pruthi notes "The leaves of this plant have been used for centuries in Southern India as a natural flavouring agent in various curries and chutneys". He adds "There are two varieties : red-veined and green-veined, the former being richer in flavour. Vacuum-shelf drying of curry leaves [gives] a better product of greenish colour than those dried by other methods".
** Phil.