I started using Dia (http://projects.gnome.org/dia/ http://projects.gnome.org/dia/) when my employer wouldn't spring for Visio. A bit quirky at times, but over

I started using Dia (http://projects.gnome.org/dia/ http://projects.gnome.org/dia/) when my employer wouldn't spring for Visio. A bit quirky at times, but overall not too bad for simple stuff.