I'm posting this for the benefit of those who come to the forum asking about the appropriateness of honeymoon funds and cash in lieu of gift requests. Someone just posted asking about this and as the comments started coming in about the rudeness of such requests, sadly the OP deleted the post
There is a difference between what some personally consider rude vs. appropriate etiquette. As I have been referred to Emily Post on more than one occasion on questions regarding wedding etiquette - I decided to check there for guidance.
Regarding cash in lieu of gift requests - http://emilypost.com/advice/is-it-okay-to-ask-for-money/
Honeymoon registries are mentioned here - http://emilypost.com/advice/wedding-registry-etiquette/