Thanks, let me add a little more detail.

I currently have a script which fires of a load of threads, to do SNMP polls on particular devices, each poll getting its own thread. I dont want to have a thread per device constantly running, especially if all its doing is sleeping.

So I suppose what I'm after is the ability to fire the same routine of (as a thread) every 20 seconds for device A, every 30 seconds for device B etc.

I was planning on reading in the device -> polling rate realtionship from a file. So it has to be a little dynamic.

Thanks again.