One of my juniors has her birthday on 29/02, and she counts herself as a four-year-old as of 2012, and to keep that clear and straight, she waits four years before celebrating her birthday just so she can celebrate it on the actual day. Basically, she counts four years as one год for herself. Gotta admire her patience...-_-''''''''''
If I was born on a leap year, I'd count how many years it's been since I was born. If I were to celebrate my birthday, I would probably celebrate it early when I'm not on a leap year, and on my birth дата when in a leap year.
Of course, I wasn't born in a leap year, so I never have to do that sort of thing.
My father was born on Leap Day. We celebrate his birthday every year, but when it is actually the 29th we make it extra special. He has had 12 birthdays, but he is 48 years old since he has been on this planet for 48 years.
Oh, and we celebrate his birthday on February 28th или March 1st. It doesn't really matter to him.