Multi Threading in PHP

Hi, a few days ago i saw here a thread about multi threading, but this didn´t answer my question. I have a page, that must search the best price in multiple databases/plain text files and perhaps one day xml-interfaces, some of them can be located on extern hosts, every search can be a single function/object method. In my dreams i call this in multi thread (with a timeout functionality) to handle lost connections or anything else that would cause endless queries, and return after this to print out the results. Is this possible with any function today? Or will this be possible in future? Best Regards, Bart Frackiewicz