Loop of WWW - force sleep

How do you force sleep intervals when you have a WWW called each time in a for loop of arbitrary iteration

If you need to wait for the www call to complete you can just yiel return the call from a coroutine or use the ASyncResult returned by the call to react when the call completes. Normally you would use Thread.Sleep(time) to set sleep intervals, but this is considered bad coding practice in general and will probably crash when used in the unity gameloop.