Changed to Python!

To run the script copy the file

"gn_toggleBoneLabels.py"

to your maya scripts dir ("c:...maya2009scripts" )

Then type this in your script editor:
import gn_toggleBoneLabels

Now you can run the script with this command:
gn_toggleBoneLabels.labelBones()

MEL Users just copy the MEL Code out of the python file and run it directly in the editor
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!!! Changed the whole approach !!!

You can now select the Label in the Viewport and your corresponding Joint will be selected.
Run the script and all selected Joint will be labeled. Run it again to delete the labels.

You can now even turn of Joint Display for a more cleaned up Viewport and still manipulate the joints...

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This tiny Helper toggles the Labels of all selected Bones.

This is useful for Skinning (Scene Navigation in general)

The Labelname is taken from the Bonename. If you change the Bonenames run the script again

Just copy the content of the mel script in your script editor and drag it to your shelf bar.