How do I shrink the Unity launcher icons to make them smaller? [duplicate]

12.04 and later - Unity (3D)

The launcher icon size can be changed from a new option in System Settings - Appearance

You'll see a slide bar which allows you to change the launcher size.

Drag left to shrink

Drag right to expand

Install ccsm from the software center . Now Press Alt + F2 and enter about:config

Then go to the Experimental tab. In the middle of the page is a slider that allows you to adjust the Launcher icon size from 32 to 64 pixels. You can also control backlighting and attention animations.

You should install MyUnity. You can see icon size option.

Just set "Size".

Using Ubuntu tweak under tweaks -> unity:

It is possible as of the latest Unity update.

Checkout my answer on How can I configure Unity? for details.