WordPress constants such as WP_DEBUG can be defined in wp-config.php but have to be edited manually everytime you need to make a change. But no longer! You can now edit several common wp-config.php constants directly from within the WordPress admin!
Download the latest version of Config Constants here.
The current list of WordPress constants you can modify with Config Constants are:
More constants will be supported in future versions.
This Plugin allows you to control WordPress constants in an organic way as it won’t seek to insert any constants not already found in wp-config.php. So YOU still remain in control of what is in there at all times. The Plugin only modifies existing defined constants.
Also, a key feature of the Plugin is the support for two-way editing. This means you can still edit wp-config.php constants manually if you wish and your changes will be automatically syncronised with Plugin settings. Likewise, if you update the value of a constant via the Plugin options page then wp-config.php is immediately updated.
Let me know what you think in the comments below.