Someone had our wedding invitation set in a beautiful frame. I would have never done it myself and it is one of the things I love most. I think about that person every time I see it.
Obviously it doesn't cost $150 dollars, but you could do that and a gift card to where they are registered so they can put it towards the big ticket items. (Honestly, the kitchen/house stuff is great and so useful and what you really want but you don't remember or think of the gift giver when you use it)