Review OmniGraffle
How it will save time: OmniGraffle is just plain easier to use than Visio. Once you download some IA-related stencils, you will be diagramming in no time.
Comments: OmniGraffle only gets three stars from this reviewer. While easier to use and prettier than Visio this is still primarily a diagramming tool -- and a diagramming tool not orginally intended to do wireframes for websites. While it does allow the user to diagram using pixels (Visio does not) you still must download third-party stencils to do your work. IA-related work is not native to this platform. Not that the support is bad. There are plenty of stencils and templates available, just the work could be done faster if the developers built a dedicated IA-related tool.