I'm pretty sure there's nothing romantic about shoving a USB flash drive into a Swarovski engagement ring. First of all, if you're buying a Swarovski engagement ring rather than a diamond one you're probably already in trouble. But adding in a USB drive? Come on, dude.
I mean, sure, you could load it up with romantic pictures of that vacation you once took together to Pennsylvania Dutch country, but you really don't need to carry that around with you everywhere. I know you like a good gimmick, but just stop and think about this one for a second. An engagement ring is probably not a great thing to mess around with. But hey, you're the expert.