What was the most challenging technical proposal that you've ever written?

The use of basalt fibre rebar in rocket protecting concrete walls in Basra....by searching for the loads the rockets produce I think I am now on somekind of Blacklist ......all for the well being of the people in Basra...

I wrote a proposal in my undergraduate as a final year project on "Deployment of IPv6 in Intra lab Environment".

I have written a proposal on "A GIS Tool for WiMAX Network Planning".