Luke Gedeon

The default position for the menu in WordPress 2.7 is on the left, but since the scroll-bar is on the right, some people wanted the menu over there too. Plus a lot of blogs/websites have menus on the right so menu on the right seems to be a pretty popular option.
This plug-in moves WordPress admin menu to the right side of the screen.

Admin Menu on Right

Moves WordPress admin menu to the right side of the screen.

chaimchaikin

Admin Menu Groups allows you to create nested menus in the WordPress admin sidebar navigation and organize all menu 
items in groups as needed.
A few notes about the sections above:
<ul>
<li>Create groups to organize the admin menu</li>
<li>Put less frequently used or advanced options in their own group</li>
<li>Hide unused items in the admin menu</li>
<li>Group related menu items</li>
</ul>

Admin Menu Groups

This is an underrated plugin. It is exactly what I expected: Keep my admin menu tidy since I see it almost everyday.

Especially impressive drag and drop tool. So I can make it works without finding any documentation like common plugins.

Thank you!

Underrated plugin

Admin Menu Groups allows you to create nested menus in the WordPress admin sidebar navigation and organize all menu items in groups as needed.

Admin Menu on Right vs Admin Menu Groups