GIMP Plugin Registry

Mine is 50 Kb.
If you want to get smaller binaries, just add -CFLAGS=s at the end of your compilation command line (under Windows or Linux). This switch tells the compiler to strip debug code. I don't know why it most people forget that option: even when you compile Gimp under Linux, which nearly anybody can do easily), it can save much space on your HD.
Under Windows, don't forget to add LDFLAGS=mwindows: this switch tells the linker to create a console-free Windows executable.