I tracked down a compatible RG11/ RG12/RG45 Modular Crimp Crimping Tool on eBay for only US$8.58 or Approximately AU$9.00. It is very well made and works extremely well, despite the price. It is also extremely easy to modify to make it compatible with the Lego Mindstorms NXT Cable Modular Plugs. It took me under 5 minutes to complete the modification with a Philips-Head Srewdriver and a Sharp Modelling knife.