Click-and-send giftcard for her favorite store, or a Visa Debit Card in that amount. Or just iTunes credits, they get an email notification.
As mtnbkr pointed out, that assumes the other party is plugged in.
But, even then, sometimes it's nicer to get something more personal. Maybe I want to send a birthday card with a handwritten note. Maybe I want to send a nephew a baseball card or a collector coin.
You ever receive a
scanned image of a 1898 silver dollar ? Not the same thing as getting the genuine article. You can tell the difference when you lay them side by side. The scanned image is a lot flatter.