I usually double the amount of dried parsley to get the taste. It still doesn't have the "fresh" taste that others mention, but do finds it adds something and is better than nothing. Don't get tooo carried away with increasing the amount though, very easy to overdo it.
If there is a lot of liquid in whatever I'm making, I do add the dried parsley early. It seems to rehydrate a tiny bit and I think there is more of the flavour there.
Dried basil, as casey has said, has absolutely no flavour, I don't even bother.