"Photoshop is undoubtedly more useful graphic designers, however
for making quick tweaks, nothing beats GIMP. Recently GIMP 2.6 was
released, so I decided to make this tutorial for those who still
haven't discovered the magic of GIMP and don't know how to use GIMP
productively.
"1. Rounded Corners: There is something about Rounded corners
which make Photos look very cool. So here's how you can give your
photos rounded corners: Open up the image you want to apply rounded
corners effect."