What Buttons have you changed from default in MC?

[Nintendonuts]

Sprint- Q
Toggle Perespective-R
Drop Items-Y

 

[AlgerWaterlow]

Sprint: Q
Drop: Z
F5 Mode: F4 (on one computer; the other still has it as F5)

 

[Zado]

Sprint - Shift
F5 - F
Optifine - side button on my mouse

 

[Dah_Hobbit]

Optifine: f on 1.6.4
Sprint: f on 1.7
Place block: Q

 

[Twee]

Basically all besides WASD

 

[TurtleBombPro]

Optifine Zoom:F
Drop Items:G
Sprint:R

 

[Ceroria]

Sprint: Left Shift
Sneak: Left Control
OptiFine Zoom: F
F5: The "3" button on my Razer Naga Hex
Slot 5: Q
Chat: Enter
Drop Items: R
I think that's it...

 

[Adam_I]

Sprint: E
Inventory: I
Sneak: C
Drop items: Enter

 

[WeiBeX]

This is what I changed:
-Sprint: Shift
-Crouch: LCtrl
-Optifine Zoom: F

 

[ClownCostume]

Toggle Perspective: X
Optifine Zoom: C
Sprint: Shift
Crouch: F

 

[Smizack]

Sprint: LShift
Crouch: LCtrl
Toggle Perspective: R
Zoom: Z

 

[Miko_]

F5: Side button 1 on my mouse.
9: Side button 2 on my mouse.
Drop: R.