Janis Elsts

This plugin sorts the items in the “Settings” and “Tools” dashboard menus in alphabetical order. Useful when you have lots of plugins installed and very cluttered menus as a result. The plugin should work well with most “drop-down menu” plugins and other visual enhancements.
You can configure which menus are sorted by editing the source code. Yes, hackety-hack 🙂

Sort Admin Menus

Sorts the items in the "Settings" and "Tools" menus in alphabetical order.

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.

Sort Admin Menus vs Clean WP Admin Menu