We'll create fresh WordPress site with Easy PHP Text Widget installed. You have 20 minutes to test the plugin after that site we'll be deleted.
Easy PHP Text Widget modifies the standard Text Widget of WordPress making it able to
execute PHP code.
The normal behavior of the text widget is preserved so it can be activated without
fear. That let the blog owner to control the text displayed with PHP, eg. showing different ads on different posts, pages, categories and so on.