If you like the bokeh effect in some pictures you can create it with GIMP, it may not be the same as created at the time of taking the picture (With lenses).
Check out this bokeh pictures
Well now lets see how to create kind of bokeh effect using GIMP
This is the original image:
What we first need to do, is to use the GIMP free select tool.
Then select the contour of the image you want to be highlighted, in this case the flower.
Now with the selection done, press “Ctrl+c” and then “Ctrl+v”, and go to layers view.
As you can see it appeared a new layer, a “floating selection (pasted layer)”, now right-click on it and select “new layer”
Ok, now we have two layers one with the full image and the other with only our selection.
Select now the layer with the full image, and right-click over the image itself, select the menu “filters” and then, “blur” and then “Gaussian blur”.
Select the value that better works for your image.
And the final job is here:
Hope you enjoy it, and thanks goes to: Digital Photography blogs