This 3D printing is really becoming more widely used for low-run or bespoke needs!
For your information then, yes, once an object has been designed then this data can be shared. A file in a 'standard tessellation language' format is produced; this is standard fare for CAD software that the object would be designed with.
I'm into mountain biking and was fascinated to read recently that Empire Cycles had basically constructed a prototype bike using 3D titanium printed parts! Much like you've suggested a lot of small parts were constructed which were then epoxy bonded together! Wow!
Now you've got me thinking ... maybe I could finally 'print' that Rally 037 I've always fancied...!