I've played with many different mockup applications (I've got a blog post about them I'm working on currently). I got started playing with them due to a free li

I've played with many different mockup applications (I've got a blog post about them I'm working on currently). I got started playing with them due to a free license I got from Peldi in return for blogging about it. The short answer is that the tools are efficient. A good mockup tool bridges the gap between providing enough information that you can communicate ideas and being able to do so very quickly. PowerPoint doesn't communicate the ideas as well as other tools; and it is definitely slower than other tools. Today, Balsamiq is still my tool of choice on my laptop. iMockups is my tool of choice on my iPad. One of the primary reasons is that I can export BMML files back to Balsamiq.