Ivan Popov

Super simple backup taker for wp-content folder and the database. Super useful for developers or before plugin/theme update.
Activate the plugin, go to the Simple Copy menu and take as much zip archives of your themes plugins and database as you want.
Files are saved under wp-contet/ directory.

Simple Copy

Super simple backup taker for wp-content folder and the database. Super useful for developers or before plugin/theme update.

avdude

This wordpress plugin allows you to create and download a backup of a plugin or your entire plugins directory. 
Very useful to use just before updating a plugin. 
Adds menu item to Plugins & Tools

Plugin Grabber

This wordpress plugin allows you to create and download a backup of a plugin or your entire plugins directory.

Simple Copy vs Plugin Grabber