Apple has just released iPhone OS 3.1.2 for the iPhone and also the iPod Touch.  The Update addresses some network issues, sleep/wake trouble as well as video streaming troubles.  You can get it via iTunes now.

 

This update contains bug fixes and improvements, including the following:

– Resolves sporadic issue that may cause iPhone to not wake from sleep
– Resolves intermittent issue that may interrupt cellular network services until restart
– Fixes bug that could cause occasional crash during video streaming

 

Of course if you have a Jailbroken iPhone you will want to hold off a bit to be safe.