I've been spending a lot of time this year further developing an improved garden cart idea that I originally built at Sauvie Island Organics about 5 years ago. There are now seven versions of this cart in use on farms around the NW. I've put up an explanation of the basic design features and also a print for how to make your own. If you want one but don't want to make it yourself for whatever reason I've also started working with two skilled fabricators to build these in small runs.
All of the info is at farmhandcarts.com And definitely let me know if you'd like to order one from us which will help fund development of more attachments (bike trailer hitch, flamer, bed marker, etc.)

Josh Volk
slowhandfarm.com
[email protected]