The Human Powered Pick-Up Truck.
An interesting design, worth reading through for anyone wishing to build a Trike/Cargo bike etc
LINK:
http://drumbent.com/trike.html
The Design Page:
http://drumbent.com/trikedetails1.html
BLOG: with updates of pick-up truck.
http://drumbent.blogspot.com/
Regards
Tom