RepRap Pro Ormerod iamburnys Replacement Extruder Tube Clip/Tounge
I got fed up of coming to check on a huge long print after a few hours to find the bowden tube retaining tongue had fallen out of the extruder causing no filament to be extruded, so i quickly knocked this up in OpenSCAD, not one of my best models as it is challenging to print being so small and does required support while printing the over hangs, however I managed to get one off successfully and after a bit of clean up it works as intended.
more info here http://forums.reprap.org/read.php?340,320018