This is an adjustable script, it turns any image into a circle.
This is a much older, simpler script than the current "Amazing Circles" script posted at the GIMP Registry... but you may be interested in the version there, as it has lots of other parametrers you can play with. You can find it at:
http://registry.gimp.org/node/184
; Installation: ; This script should be placed in the user or system-wide script folder. ; ; Windows Vista/7/8) ; C:\Program Files\GIMP 2\share\gimp\2.0\scripts ; or ; C:\Users\YOUR-NAME\.gimp-2.8\scripts ; ; Windows XP ; C:\Program Files\GIMP 2\share\gimp\2.0\scripts ; or ; C:\Documents and Settings\yourname\.gimp-2.8\scripts ; ; Linux ; /home/yourname/.gimp-2.8/scripts ; or ; Linux system-wide ; /usr/share/gimp/2.0/scripts
