WowAce

Type "/gcd" to open the options menu.

Clicking the "Unlock" button at the top will let you move the whole frame around as well as each icon separately.

Right click the red frame to lock them and save their positions when you are done.

General:
Here you can detach the frames from your mouse and choose for which talent specs the addon should be active.

Ring:
Options to disable the ring, change its texture and color and stop it from rotating.

Swing:
Those are the options for the swing timer.
You can change its color and size or disable it altogether.

GCD:
Those are the options for the gcd bar.
You can change its color and size or disable it altogether.

Casttime:
Those are the options for the cast bar.
Disable it, hide the default castbar, change its looks or make it show the name of the spell you are casting, its all in here.

Cooldowns:
Here you can add/remove spells whose cooldowns should be watched and displayed as icons.