I have taken to saving my objects as .gbr files which is a Gimp Brush. I keep them all in the same directory. Then whenever I want to use them I go into the preferences in Gimp and move that brush directory to the top of the list - Refresh brushes - and then I just splat them as I will using the paint brush or pencil.
You will have to add this private brush directory into the Gimp preferences list. Of course, you could just save your .gbr files to your regular brush directory but I don't like getting to much crap in there unless I need it.
Here is a picture of where you would do this: (my brush directory is the 2nd one .../brushes/brushes/ ) <-- I know it's not a real intuitive name, so what?