It's possible to give the bots on your server fake pings, but I've never heard of someone being able to fake their own ping (as a human player in the game).
The "Zero ping" thing only occurs if you're hosting a non-dedicated server. Otherwise you'll have a ping just like everybody else. On a non-dedicated server, the host player always has an advantage (however slight) from his zero ping, that's just how it is.
Last edited by Kurgan; 10-07-2010 at 10:45 PM.