My late mother had the best wedding present idea ever. Postage stamps. Even in this technological age, postage is a hidden cost of a wedding and beginning married life. She usually gave a roll (or 2) of stamps as her gift. It was easy to buy, easy to wrap, easy to mail even. It matched everything, never had to be dusted or put out on display when the giver comes to visit. My mother never had to go to a bridal registry. Even in rural areas like ours, the post office is usually handy! Many brides recalled her generosity each time they had to go buy their own postage and many told her so since she was the Postmistress!
I use the stamp books especially when I have to mail a wedding RSVP and cannot attend. I just tuck them in. If I go to a shower, I usually tape the stamps to the bottom of a shirt or other box so that they aren't easily lost. They are always a hit!