Just wondering what software you use to create a visual sitemap / site structure representation before you start big sites?

I am looking to map out a large site, but cannot find any good software to help me map the site visually (And in pages/categories)..

+1  A: 

I strongly suggest taking a look at this tool:

The Balsamiq tool is the best for doing mockups (i assume this is what you are referring too when talking about sitemaps before you start...). With this software you can quickly generate a working wireframe of what ever you are creating. So much functionality that you can actually share it with your client to get some good sign offs prior to typing the first bit of code.

Very powerful!

And the other one...just shown at the last MIX09 is SketchFlow. Couldn't remember it to save my life. This is a WAY COOL tool for site maps and UI mock up. I was trying to find you the actual MIX presentation as it is super cool to watch. But here are some YouTube videos of that presentation from a user perspective I guess.

Check it out!

update...found the SketchFlow video!!!

Great keynote from there too:

Andrew Siemer
Sorry I think I didn't explain myself enough - When I mean sitemap I mean actual map of the site... Like a mindmap/brain storm? Working out navigation structure, categories etc...
Yes...for that you want to use SketchFlow. You can actually design a sitemap that works in real time. Watch the SketchFlow video for an idea of what this it is super easy.
Andrew Siemer