Way ahead of you... watch this space ;)
UPDATE: I was already working on this and have now added it to the site! On all appropriate moves you can see if Pokemon can learn it by TM, HM or Move Tutor in Generation IV.
For example Earth Power or Dark Pulse. I didn't do anything for Gen III because I assumed that any move tutor moves from Emerald were also available in Platinum/HG/SS. But I may be wrong.