Bridal Registries were indeed good ideas, but perhaps their idea has gone upon the wayside.
I believe that people are getting older when they get married, and that the registries are really only beneficial for:
Those who marry young.
Those who are having a second marrage and their former spouse got everything.
Cases in Point:
Large numbers of couples are living together before they get married, which means when they get the wedding gifts, they already have two of everything.
Also, when teenagers go to college, they go with fully equipped entertainment systems, enough kitchen items to fill twice the space allocated to them, and random other household objects.
So really, if you already have this stuff, what are you supposed to ask for? You could always ask for better stuff, but that is wasteful.
I had this problem last year when I was filling out my bridal registry lists. Both my husband and I had enough stuff to fill two apartments. We had serious discussion about what we were supposed to ask for (kitchen or bath stuff), what was acceptable (household items), and what we were going to shy people away from(the aforementioned). We never actually got around to filling out the registries. (Well, we registered for three things, one of which just happened because I broke a strainer).
One of my coworkers is having this problem right now, only it is slightly worse for her and her future hubby. They own a house, have new appliances, furniture and pretty anything else that they could need. The only thing that they could come up with was to fill out a registry at a home improvment store so that they could re-floor their kitchen and paint their garage.
I suppose the real problem is: you can't really tell people that you want money as a gift.
Seriously, call up the marrieds-to-be, ask them if they would like a check. Even go as far as to ask if she is changing her name. They will understand that you aren't trying to get out of spending time buying them a gift. You might just be their new favorite relative or friend.
Anyhow, my favorite tangible gifts were not on the registry. We received a cool teapot from my boss, and a robotic vacuum cleaner from my best friend.