According to the date mechanics guide on gameFAQs, the maximum affection level Aerith can have is 95.

Wouldn't it be interesting if, if you had exactly the 95 maximum affection total, therw was a minigame where you could go down and retrieve the white materia?

Of course, you couldn't use it to such dramatic effect as Aerith herself does, but perhaps you could use it to cast the 'holy' spells so common to the FFGenre?

Having the White Materia might also trigger an extra hidden cutscene when you see Aerith's hand in the final FMV.

Just a wierd thought I had...

you know that's interesting that you mention that, because I was thinking just a few days ago that it would be cool if you could go and retrieve the white materia from the water. Cloud can keep it as a memento of Aerith.

That sounds interesting. I would play it. but what would the extra scene look like? I would guess that Aeris would either come out revived or take Cloud's hand and bring him in the Lifestream with her. He did protect her through out the first disc.

Here is what I think would happen if Aeris took Cloud in the Lifestream:

Aeris is reaching out her to Cloud
Aeris: Take my hand Cloud and I will protect you.
Cloud holding out his to Aeris
Aeris: I cannot hold this portal open, please take my hand.
Cloud: Will I be able to see you again?
Aeris: I have never left you, I have always been there for you when needed me.
Cloud: Even when I fell in the Lifestream in Mideel?
Aeris: Yes, and I helped you find the truth about your past.
Cloud takes Aeris's hand and is taken in the Lifestream, Aeris stands in front of him as an angel. Cloud and Aeris embrace each other.
Cloud: You are very beautiful. Never have I seen someone so beautiful in my life.
Aeris: It is my turn to protect you.
Scene flashes to Tifa looking for Cloud, but can't find him.