This one?
Well, after reading Megura's FAQ on FF7 changes...
There were some added Materia in the game, the Japanese version had 6 that were disabled.
Ruby Fragment and Emerald Fragment were key items that did nothing, these items were replaced with Desert Rose and Earth Harp when they added the new Weapons.
Instead of 6 characters for your name, you had 9 in the US.
Sephiroth's Supernova attack was redone (I've seen the Japanese version of it... it was short...)
There was also a Final Fantasy International, which was Final Fantasy 7 but with added stuff (just like Final Fantasy X: International)
Also some text changes between the Japanese and the US.
- 'Gold Needle' became 'Soft'
- 'Twin Head' became 'Schizo'
- 'Gravity' became 'Demi'
- 'Heavy Shot' became 'Big Shot'
- 'Pyro Holes' became 'Pale Horse'
Square wanted to add Multi endings... but lack of money.
Extra summons... Golem from FF5 was suppose to be in it but they said the game would be too easy with it... so no.
Yuffie had the Rising Sun weapon in the US but was disabled in the Japanese version. Reason? No one really knows.
And Cloud was supposed to be able to swim underwater and you could use the sub or swim all over the world. However, in the final, you can only go around the center of tha map.
Well... that is what Kao Megura said in his FAQ =P