This is what I am hearing from those who plug honeymoon registries:
"We have a fully furnished house and we don't need anything for our house. We've been living on our own for a while and have all the sheets and towels and pots and pans that we need, besides, we want to choose our own furnishings instead of leaving the choice up to other people.
We do not, however, have enough money to fund the type of honeymoon we want. We could just drive 100 miles to The Lake and stay in Aunt Edna's cabin for a week, but we'd rather go to Fiji flying First Class. Therefore we are going to figure out a way to get our wedding guests pay for the honeymoon we cannot afford to pay for ourselves. We'll do this with a honeymoon registry where people think they are buying us an 'experience', but are really just giving us cash, minus the cut taken out by the web hosts."
If that is the case, and if the couple really prefers money over any other wedding present, then they are best advised to SKIP REGISTRIES ALTOGETHER. If anyone asks "Dear, where are you registered?", you can reply "No where." "But I want to get you something you will enjoy." "I hope you won't be offended if I tell you what we really want is a great honeymoon, and we are hoping for cash presents. We don't want to 'register for cash' so we just did not register anywhere. I'd be obliged if you would help spread the word in a polite way."
My fiance and I are in a similar position, and we debated for a while but in the end chose to register online for cash (Deposit Gift - it's awesome!) and boy are we glad we did! Sure there were a couple of nay sayers, but everyone has different views of tradition and taste and in the end we did what's best for us. For the most part, everyone has loved it so far and we're getting gifts that will actually make a difference in our lives - without this we totally couldn't afford the downpayment on our house. Not all of the sites out there are a good idea, but Deposit a Gift is great because it gives you all these ideas and templates for what works really well. Totally recommend it!
I guess some people do use honeymoon registries to pay for pretty much the entire honeymoon, but this isn't recommended - even by some of the honeymoon registries themselves. That would be like planning on moving in together after the wedding with only the things that your guests have given you. If you don't get any silverware, what will you do, just eat with your fingers?
I personally think it's silly to plan anything based on the gifts you think your guests will be generous enough to give you. That's why my fiance and I are planning on taking the honeymoon we can afford on our own, but putting some ideas for upgrades and extra activities that we wouldn't otherwise do on our honeymoon registry. We aren't asking guests to pay for our honeymoon. We're merely giving them the option of gifting us with an experience rather than a physical gift.