DevShed has posted the second-to-last part of their tutorial series about creating a Twitter "badge" for your site with the custom icon and latest tweet pulled from the site. This new part looks at handling exceptions thrown by their class.
This application serves a single purpose. It accepts an input and delivers an image to the browser. In the event of an error, the script halts execution and displays that error. The problem lies in this difference in output. The calling page is expecting an image and therefore won't display the error text. So to make this useful, it might be a good idea to deliver the error text as an image instead.