A regular chainstay, and my Chainstay.
How about Civia Cycles, Loring? This bicycle is really nice. Brooks saddle, Avid DISC brakes, Mavic Rims, Truvative Stem, Post, & cranks, bamboo fenders. It's an internal 3 speed. As you all know, I'm no stranger to the 3 speed. For a Cargo/Commuter I'd have liked it to have a 5+ speed, but a 3 speed will work just fine.
Check it Bleed! Bamboo for the rack panels.
How about this? Combined with the double kickstand, this spring will keep the wheel straight while it's parked, so your bike doesn't tip over and you loose your cargo. Now that's thinking outside the box, before long we are going to see these types of add-ons everywhere. as Banksy says, "Think outside the box, collapse the box, and take a f'ing sharp knife to it."
A Banksy picture that pretty much seems up the currect global conciousness.