blas

Neat Admin Menu allows each user of the WP Admin to customize the appearance of the admin menu.
Users can arrange the order of menu items, or hide the ones they don’t need.

Neat Admin Menu

This plugin allows each WP user to customize the appearance of the admin menu, by hiding and arranging the order of the menu items.

borantula

Most of the plugins and even standart WordPress tabs in the admin menu are not used very often. 
With this plugin you can make rarely used items in the admin menu invisible until you need them. 
You can just toggle them whenever you need them with Toggle Extra button in the left menu.

Clean WP Admin Menu

Still works!

You can make rarely used items in the admin menu hidden.

Neat Admin Menu vs Clean WP Admin Menu