- inSSIDer (http://www.metageek.net/products/inssider/)
- Heat Mapper (http://www.ekahau.com/products/heatmapper/overview.html)
Heat Mapper is a site mapping tool that you can use to identify signal strength at various locations in your organization. First, you import a graphic with your floor plan. Then you wander around with your laptop running Heat Mapper and click on the map corresponding to where you are. When you are done, it generates a map that shows signal strength in different areas on the map. It is displays much like a topographical map. There are more advanced paid versions of this product, but this one does a nice job for free.
I'm going to be keeping both of these tools on my laptop.