Dof Object - set the depth of field to an object - set in the camera edit panel but the distance is calculated on the camera object only so linked cameras work.

Alt+Period - sets active pivot

some tooltips didnt make much sense, edited a few.

source/blender/src/space.c

@@ -2475,7 +2475,9 @@ static void winqreadview3dspace(ScrArea *sa, void *spacedata, BWinEvent *evt)
 			case PERIODKEY:
 				if(G.qual==LR_CTRLKEY) {
 					G.vd->around= V3D_LOCAL;
-				} 	else if(G.qual==0) {
+				} else if(G.qual==LR_ALTKEY) {
+					G.vd->around= V3D_ACTIVE;
+				} else if(G.qual==0) {
 					G.vd->around= V3D_CURSOR;
 				}
 				handle_view3d_around();