I didn't pick though it showed a local number- tried calling back after giving it an opportunity to leave a VM.
This is apparently a spoofed caller id since calling back under a *67 anonimizer code gets a message that rings then answers with a message about ..."reached a number that is no longer in service... Error twt5", repeating for at least five times. By leaving it on the hook, the message then changed after ringing aggain, to "lines are temporarily busy..code, Oh 1 zero 6" repeating until it made a sound (four note repeat) that most people would recognize as the sound when reaching a number no longer in service. however it loses the rythme and changes to a five note sound, goes back and then repeats the off beat until finally hanging up. I may have tied up their robo-caller about 8 minutes.
A check on my caller ID showed that they had called on July 16th as well without leaving a VM. Since I didn't recognize the number, and didn't find it in a Ph Book reverse search to have any identifying info, I left it alone. Since they may call again, I'll post here so it can be searched and immediately ID'd to a spoof by most likely a telemarketer.

have been called by this number several times.  I answered once and noone was there. Whoever is calling has never left a message.

Same here.  no message

I received a call on Thu, Sep 30, 2010 at 5:15pm EST from 919-573-8158 and it rang about 3 or 4 times in my pocket.  When I answered, I said the usual, "Hello", but received no answer back.  I believe my phone showed that I was on the call for 4 seconds before they hung up.