How many joints can you crack and how? Pretty straight forward.

Here's my list, from top to bottom:

1. Jaw; by opening and pushing on joint at the same time
2. Neck; either by tilting my head either side, or by turning my head to full turn and pushing with my hand
3. Middle of my back; by pulling my shoulders back, or by lifting my arms and pulling them down whilst pulling my shoulders back (like the movement you'd do on the lat machine at the gym)
4. Elbows; by extending my arms quickly from bent to full lock out
5. Wrists; by pulling and twisting my hand whilst flexing the wrist
6. Hand (fleshy bit where the thumb meets the hand); by pressing on the fleshy bit of the hand next to the thumb and bending the thumb back
7. Fingers/Knuckles; everyone's favourite - by pressing the fingers down onto the hand at the knuckles, or by twisting the fingers individually at the joints
8. Lower back; by twisting my trunk at the waist
9. Ankles; by fully extending my foot and pushing it further either with my hand or the other foot
10. Toes; either by flexing the toes hard, or by pulling them individually at the joints

I tend to crack my elbows after a period of them being relatively still - ie: after a while being at the desk/computer. I just extend my arms quickly to lockout and crack.