I found out about a great piece of Mockup software to quickly generate a mockup screen for your applications called Balsamiq Mockups. The software is distributed as an Adobe Air application that you can install locally to your PC.

Mockups For Desktop allows you to work on your UI wherever you are, regardless of your Internet connection. It works on planes, at coffee shops, and wherever you like to do uninterrupted work. Import and Export features ensure seamless integration with all the other versions of Mockups, for when you get back online. Plus you can load and save multiple mockups files, use all keyboard shortcuts and lots more.

Here is an example screen mockup that you can create in the software:

I was able to quickly create a web page template as a demo for a project that I am working on in only a few minutes of work. The Balsamiq Mockup software has many templates to use to create mockups. You can even create your own templates or download more at http://www.mockupstogo.net/.

I have not had any problems with the application so far and would recommend you trying it out on your next project as a quick way to mockup a screen for a presentation to your customers or to be used by your developers to create the real screen.