I'm gonna add a point to what Seven said: don't pick a cutesy spelling just because it looks cute. I knew an Aimee who was CONSTANTLY correcting everyone. That had to have become annoying.
Also, make sure it's something the other kids can't use against your kid at school. I had to tell my aunt that naming her daughter Diana Maria for her first and middle names wasn't such a good idea.
That being said, though, I always liked the name Diana and might use it if I have a girl. But it needs to sound good with the rest of the names, too. If I end up marrying my boyfriend, his last name ends with an A, so any girls' names ending with A might sound strange. Depends.