[BNM] PHP. Any recommendations for running a php process asynchronously?

[AndrewGill73@gmail.com]

Hello BNM,
I'm running a php script that sends google chat (xmpp) messages to
approx 20 users. It works well but the script takes approx 2 seconds
to run for each user so takes 40 seconds to run in total (too slow).

So I'm thinking about running this php process asynchronously - it
needs to run reliably on fairly standard windows or unix shared hosted
environments.

I was wondering if anyone knows the best way of doing this?

Below are a few approaches I'm thinking about:

popen()
proc_open()
exec() - then run wget.

Are there any better approaches?? Any ideas or experiences most
gratefully received!

cheers,
Andy Gill