Cumpleanos feliz a mi hermana

My little sister is 24 today. Our gift exchanging (my bday is 2 months after hers) has become cheerfully scattershot since we became adults. If I get ahold of her today, I'm just asking for a serial number and an Amazon.com address. Not as much mystery as the old days, I guess, but because she's planning her wedding she'll have to get used to telling people what she wants them to get her.

Would it be tacky to set up a gift registry for one's own birthday? I have less than two months to decide.