Got an InkShield? Here is a bracket that will mount it on the X-carriage of your Prusa. Probably works for lots of other printers as well since it puts the printing end of the cartridge down about the same distance as the tip of most nozzles.
Have a look at the Instructions tab for more details. This bracket should open the door to lots of interesting experiments with the InkShield.

All pretty simple. Print the part then mount the cartridge carrier that comes with the InkShield. I used 2-56 screws. You may need to alter the spacing of the holes that hold the bracket to your X-carriage. I have included the FreeCAD source file. If you print the stl file, note that I have already run it through netfabb.
I set up the InkShield demo files to start with a button press so that I could control when the printing started. The results of several experiments are shown. Best results were when printing from right to left at 8000 mm/minute. YMMV.