- Option is in EditButtons, Armature panel. - Currently only local X-axis mirror (seems to be default anyway) - Transform then applies changes to the mirrored-name bone as well. - Extrude: also does the counterpart Bone - New: SHIFT+E extrude: extrudes 2 mirrored Bones out of a normal Bone. (creating names by appening _L and _R) Or in short: you can now model a full rig without any manual naming! Of course the names are not too nice... a couple of ideas to explore; - rename a mirrored bone renames counterpart too - allow in weightpaint mode to select Bones - and of course mirrored edit in PoseMode (if that's useful...) Important note: I tweaked the naming convention a bit; names like Bone_L.005 and Bone_R.005 are considered counterparts. However, if you use the "Flip names" option, the number extension is still truncated. BTW: Commits in Zr's code are fixes for gcc warnings. :)