I don't know how well it makes sense to create a different birthday or wedding gift campaign off of Bitcoin but it makes more sense to gift Bitcoin directly to someone instead of still turning it to a physical present of any kind.
It's good for Bitcoin adoption but before you choose bitcoin, Bitcoin giftcard ... as your gifts to someone, you must make sure of two things.
The gift receiver knew how to use bitcoin, it's best situation.
The gift receiver possibly don't know how to use bitcoin, and you must be ready to teach him/ her about that.
If you are ready with both scenarios, it's good to go with gifts related to bitcoin.
There are many P2P marketplaces where you can trade your giftcards related to bitcoin.