What is the easiest and fastest way to gain AP?

As the topic asks, how so? I need AP fast because I want my Final Attack materia maxed and I will soon be getting Shield materia, so I'd like that maxed as well.

Just training in the NC would be the best

....Or you could get the apocalypse sword from the Anchient forest and make sure you get the W-item materia, then travel to the final dungeon until you come by magic pots , make sure to use the 99 items cheat to get 99 elixers, then just equip the materia you want to level up to Clouds apocalypse, and give magic pot`s an elixer and kill them this will give you tons of ap and exp really quickly!!!

oh yer
and theres that

Fighting the Weapon monsters would give them a massive boost.

Hehe, well, that was the point of getting the AP. Ok, this magic pot thing, how much exp and ap does it give?

It gives about 1000 AP. Exp... I forgot. I have to fight him again.

The ord things in the 'tropicl' area in the NC is one ov the best, aside from the Magic Pot.

That's what I did, was go into the Northern Crater. I mastered every materia I had (which I'm pretty sure was all of 'em), including Summons (damn, that took a while), many more than once. Then, I went to whatever-the-hell-that-place-is (forgot...where Red XIII is from) and got the Master Summon, Master Magic, and Master Command materias...then I went back and got another Master Summon, and two more Master Magic, and whupped the Weapons' asses. (Was there another Master materia?)

Master Magic, Summon, and Ability.

Though technically the Master Ability isn't really the master, because it misses out a few commands.

Like Enemy Skill?

best AP gaining party is:
Cloud with his Appocolypse(3 3x slot)
Cid with his Javalin (5 2x slot i think)
and who else? who will be the 3rd person?

and with Run armor ofcouse :)

and btw are there any 3x armor?

Movers In the Northern Crater and Cid Equiped with..... I think Trident which has 2 slots with 3x AP
P.S. How Do you get Final Attack and The Master Materias, I got one set from beating Jewel Weapon (Had to Cheat)

3x 2 only 6 :)
2x 5 is 10 ^_^

get final attack by beating fight thingy at golden saucer
and after a few time beating it... u get invite to a special arena and fight :P if u win u get final attack... if u die... u walk home