Generate toString() is a plugin to IDEA.

The plugin adds a new toString() action in the generate menu (alt + ins). The action generates a toString() method that dumps the classes fields. Java body code is generated using Velocity and you can fully customize this. The plugin has it's own settings (ctrl + alt + s). Full documentation included (Click the link from Settings).

See Features and the other Wiki pages.

Active the generate mini menu by pressing (alt + ins):