The rapid innovation of the Iraqi open source insurgency is yielding improvements in guerrilla technology. In the words of one British Army bomb disposal officer, "These guys have picked up in two years what it took the IRA a quarter-century to learn." 
The most recent innovation (after the arrival of shaped charges) gaining popularity are infrared triggers for IEDs (improvised explosive devices). These triggers are a conversion of the simple "light" beams used in burglar alarms (see image) and as safety mechanisms on garage doors. The beams are activated remotely by radio controls when a patrol approaches. When the light beam is crossed the bomb goes off. Unfortunately, unlike radio controls the beams are not easily jammed. These new triggers have been used in numerous deadly attacks on British forces over the last several months.
The most recent innovation (after the arrival of shaped charges) gaining popularity are infrared triggers for IEDs (improvised explosive devices). These triggers are a conversion of the simple "light" beams used in burglar alarms (see image) and as safety mechanisms on garage doors. The beams are activated remotely by radio controls when a patrol approaches. When the light beam is crossed the bomb goes off. Unfortunately, unlike radio controls the beams are not easily jammed. These new triggers have been used in numerous deadly attacks on British forces over the last several months.
This innovation may be due to Iranian involvement, but a more probable explanation is that the insurgency itself is finding low-tech solutions to difficult problems through an open source development process. Regardless, this innovation will rapidly proliferate throughout Iraq. Our problem is that the cycles of innovation that yield deployable counter-measures for US and British forces are slow and non-responsive by comparison. This is another aspect of global guerrilla math: our deployed innovation is measured in years and theirs in months. -OR- that a $1.2 billion program for IED counter-measures could be trumped by a $10 burglar alarm sensor.
NOTE: One potential solution is to use private military forces (PMCs) to provide IED detection and clearing services to US military units on patrol. Small PMCs would be able to circumvent the military acquisitions system to source, test, and deploy the best equipment faster.