PHP is not a parallel capable programming language (someone would argue it is hard to state that PHP is a [anything]-capable programming language at all), but there are area where this could be parallelized some way. And these are the active waiting routine. The ideal scenario for a trival pseudo parallelization is a bundle of possible time wasting operation (underterministic waiting I/O) and a good decoupling of classes of the remaining project.
Ideas born someway and so first let me say how is born this.
I found this classes looking for an object oriented binding of curl function, it was released under MIT license by James Socol. This was more than I was looking for and make me thing about it. I adapted it to my need.
Of course I am talking about the idea of implement it in PHP and this particular task.
The CurlParallel GitHub repository