Olaf Diegel is custom 3d printed guitar maker who will guide you trough the process of creating a fully functional SLS 3d printed electric guitar.
You will need the access to more serious equipment like SLS 3d printer and some tools, but they are much more available now and will probably be ubiquitous in the future.
The bodies of his guitars were 3D printed out of Duraform material (Nylon), on a 3D Systems sPro selective laser sintering system (SLS).
How does the 3d printed nylon guitar sound? Here is the answer:
He also made a 3d printed saxophone.
Update (27.9.2014):
Olaf Diegel organized "first concert" of live band that plays with 3d printed instruments:
The first live concert with a band consisting only of 3D-printed instruments has taken place at Lund University in Sweden. The band included a drum, keyboard and two guitars, all 3D-printed by Lund University professor Olaf Diegel. The band members were students at Lund University’s Malmö Academy of Music.As some comments say, the drums may sound somewhat hollow and electric guitar is not effected by acoustic properties of the body but more by electronics and coils. Still it is a nice accomplishment.