I just gave a baby shower for my daughter-in-law a few weeks ago. It was very traditional. I put on the invitation where she was registered. I had a luncheon, and played baby shower bingo while she opened the gifts. My son and DIL are from out of town so stayed at our house that night. She came right into the house, set down and wrote out the thank yous.
I would have a hard time getting an invitation telling me they want gift cards.