As you know, because you are part of it, the 3D Printing community is very active and has already designed a huge number of very good ideas.
This blog post is the opportunity to have an overview of what type of objects are already created, what is the result in the real world and perhaps try to find other news ideas.
Shakuhachi Flute ; This is a Japanese flute made of 3D printed steel
This camera lens was 3D printed and it is able to take some pictures. You can check out some pictures HERE
3D printing is also on of the best process for artists. This a one of the best exemple.
Healthcare can now be able to change a foot, tooth, bone, etc by exactly the same part, 3D printed
Great exemple of what we can do for home design. Moreover, great designers as TOM DIXON works on this topic : http://www.mostdisruptingdesign.com/
These are two exemples of how 3D printing could be easy to produce, sell and available for everybody
http://3dpcase.sculpteo.com/en/
These other exemples could also give you some news great ideas ;)