is really fascinating. Its a particle theory where the particle explores all paths. Each path is represented by an 'arrow' whose orientation is determined by the particles path and the time it takes the particle to traverse the path. The arrows are connected [head to tail]. Once all the arrows [paths] are represented a final 'resultant arrow' connects the 'beginning to end' of the chain of arrows. The square of the length of the 'resultant arrow' is the probability amplitude that the particle will be detected in the experiment [such as a photon being detected by a photmultiplier in the two slit experiment]. This probability amplitude is the same result the Schrodinger wave equation renders. Edwin Taylor has a free pc program based on this
http://ojps.aip.org/getpdf/servlet/GetPDFServlet?filetype=pdf&id=CPHYE2000012000002000190000001&idtype=cvips
You can get it here.
http://www.eftaylor.com/download.html#quantum