I made a bracket to hang my guitar on the wall. It holds my Squier showmaster which almost weighs about 4KG.
Update: Added a new version. "Guitar bracket - v2.stl"
Update 6th march '13: Added 85mm arms version.
Update October 30 2015: Changed bracket a bit. Also added 84mm arms version of origional bracket. Added smaller bracket with screw holes inbetween arms.
I printed it on 0.2mm 100% infill and 1 on 0.3mm and 80% infill which is also strong enough.