I used Visio for the longest time. This year though, I began using balsamiq (http://www.balsamiq.com/ http://www.balsamiq.com/) and I am extremely happy with it

I used Visio for the longest time. This year though, I began using balsamiq (http://www.balsamiq.com/ http://www.balsamiq.com/) and I am extremely happy with it. I have also seen Jetstrap (https://www.jetstrap.com/ https://www.jetstrap.com/) and it looks very cool but haven't tried it myself. [EDIT] Fixed Typo.