While surfing the net I stumbled on these pages. Projects people have done where GFA was used in some manner. I find this sort of thing interesting.
http://www.pagetable.com/?p=32
http://www.skytec-engineering.de/hpa.htm
If you find other such sites post them here.
Hint: If you don't want to read the entire article, just search for 'gfa' on the pages.