Both Mac OSX and Windows versions of ZiPhone are available and can be downloaded here. According to the ZiPhone instructions, jailbreaking with the utility is as easy as connecting your iPhone to its dock and running ZiPhone (users with no IMEI, no WiFi, and/or no baseband may have to boot the phone in restore mode and run ZiPhone with the '-u' option). After that, just follow the on screen instructions.

We haven't tested ZiPhone first hand yet, so we can't speak personally to the results. Though some users are experiencing problems, many are reporting successfully jailbroken iPhones after using ZiPhone. More information is available on Zibri's blog and supposedly the source will be released on the iPhone Elite Team's page later today.

Stay tuned for more information regarding ZiPhone.