Listed below are rules variations used by me and others who have submitted theirs to this site.
Send me your rules variations and I will put them up.

Axis and Allies Drinking Game
Diplomacy-style Axis and Allies by Paul Thronson
Battleship Mode
Alternative Axis & Allies
Command and Control World War 3: NATO vs Warsaw Pact
Maxgamer Blind Rules
The Split Board Game
Axis & Allies Enhanced Realism Rules
Global Crisis by Dr. Shade
Plotted Axis & Allies
Table Tactics