To make an usbtiny programmer usable directly as user from avrdude or the arduino toolkit, add the following line to a new file in /etc/udev/ :ATTRS{idVendor}=="1781", ATTRS{idProduct}=="0c9f", MODE="0664", GROUP="plugdev"
I created a file called /etc/udev/joost.rules with this line.
Reload udev with /etc/init.d/udev reload
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