Here are some pictures of a small valved pulse jet that I have created:

Startup is created with a sparkler (It gets ejected upon sucessfull startup).  The vavles take a nice beating (take a look at the next picture).  I am working on different vavle setups in order to create the right amount of power.  At only 2.5 ft. long each, two of these should produce enough force for a small go cart.  Other fuels (than propane) are being explored.  I will hopefully have some new pictures (possibly some video) up shortly.