We're using my registry. Allows you to add from multiple websites and we love that you can add gift cards and a cashfund on the same site. We've lived together for 6 years so have a lot of gift cards added and a few gifts because we would rather someone buy something listed than get our 3rd waffle iron.
My fiance and I aren't doing a registry since we own a home already and don't really need anything! We are though having an insert with our invites stating that if our guests would like to give us something that a monetary gift is something that we suggest