I am perosnally more interested in front-loaders. Like this one: http://www.smallroomsoftware.com/files/LIGHT3115.jpg

I've driven several trikes, all with regular rim brakes, and it's fine. Another factor is that when you are hauling cargo you will naturally start predicting traffic much more ahead and therefore have to brake much less.
The frontloaders are very popular in Denmark since the 70's. and the bike I linked just now (called a christiania bike, invented and fabricated in the freetown in copenhagen) tends to ride for decades with little trouble. People use them to transport two kids and groceries. All romantic and shit, but fucking useful too.

I know a skilled metalworker who is very interested in building cargobikes too. The bohemian blacksmith: http://bohemianblacksmith.com/ When the time comes that we are ready to start sketching and planning (think ing after burning man), I will put him in the loop. He knows his shit on all sorts of metal.

Wgile him at it, I'd like to try and design and build one from scratch, for the heck of it. Should be a good experience. Biggest obstacle: getting/making a jig for bike frames.
    After that, I'd like to experiment building front-loaders out of hacked up frames. using a full frame with a modified fork, namely. Should be quite easy. Though we need to get some TIG welding down. :)

OMI! Also, this Saturday, we shall kick balls. Aleric and Nick from wikiseat might come over too, they both moved to Oakland very recently. Very awesome!