A Separate Process?

Is there any way to make a separate process in PHP? I do real-time stats collection on my site and one of the things I collect is the domain of the user (to get their country). Sometimes getting the domain name takes a few seconds to come back and the user has to wait for that time before their page displays. Is there any way to split of a separate process - that doesn't end when the current process ends - to do the stats collecting so that the user doesn't have to wait? Or, if not, is there some way to tell the browser that it has all the data (so that it will finish rendering the page and run my javascript) and the script can continue running and do the ns lookup? I'm sorry if this question has been asked and answered before but I couldn't find an answer anywhere else... and the archive for this list seems to be down. Jordan