This is a bike D-lock holder that I created out of surprise when I tried and couldn't find one.
This is a universal holder. It will hold any D-lock.
I know that some come with an in-built clip, but this design is for the other 99% of locks! It will also come in handy when the in-built clip inveitably breaks on an otherwise great and expensive lock.
The version here is the 6th iteration. It has been partly hollowed, reducing the cost by 25%.
The 4th version (pictured) has successfully ridden 400km attached to the seat post on my bike, with lock attached. I recommend using a simple 3" rubber strap, hooked into the holes on the sides of the holder. That will keep it in place even during downhill rides. I'm quite surprised at how expensive the Shapeways quote has come out, but I thought I'd put the design out there for the benefit of others who couldn't otherwise have one. As such, there is no markup applied on this design. I'm working on iteration 7 now, which will try to do the same thing in one quarter of the volume, but that won't be available until around Jan 2014.
You'll need two small bolts. The holder has a recess on each side that will gently hold a M2 or M3 nut captive, so you can use any bolt you like. If you don't have any around, you can pick up a pair for about 20 cents. I used two leftover m2 bolts I had from an Ikea furniture kit.
It is suitable for a 28mm - 32mm bike seat post. If you're not sure what your seat post diameter is, it'll probably fit - It was designed for my bike, which is nothing fancy, just a pretty common low cost road bike available in Australia with fairly standard lengths and components.