Get dimension of selected part of mesh? is there a way to get the dimensions (bounding-box scale) of a selected part of a mesh? Right now I have to do the following steps to get that information: 


duplicate the selected part of the mesh
part it
switch to object mode
select the new object
finally read the dimension in the right bar
delete the object (cause I don't need it anymore)
select the other object again
switch back to edit mode to continue work ...


Since I have to do this very often I would welcome a shortcut or something ...

EDIT: the addon presented here comes close to what I'm looking for. Unfortunately the panel closes every time I change the selection and has to be reopened via menu ...
Many thanks
I think this should help. when you are in edit mode, turn on this edge/face infos from the N key menu. this will show the scales of the parts you select.