How can I gift a copy of an app that I already own?
The gift function is embedded in the small triangle control to the right of the Buy|Download text - almost looking like it's the same button on iTunes for a computer.
Just click the square button and select Gift This App. On iOS you will want to press the rectangle with the arrow key and select Gift.
If you hit the "share" button (if I'm calling it that correctly, it looks like a square with an arrow pointing up from it). One of the options is "gift".