Its incredibly easy to use, and both OS X and Windows versions are included in the download. Instructions from the readme:
Connect a brand new phone to the dock.
Run the program
Well, you can also use a restored phone...
Or a normal in use phone...
Well... whatever !
Run the program

Well, you can also use a restored phone...
Or a normal in use phone...
Well... whatever !
OS X download the app here, or if you're not an MMi member you can download it here.
If you would like to compile the latest version the SVN is located: http://iphone-elite.googlecode.com/svn/trunk/ZiPhone/
Here's how to use the app:
Tutorial for noobs:
1. Put iPhone in Dock
2. Copy all files under C:
3. Start/Run --> write cmd --> Hit Enter
4. Drag ziphone.exe into the cmd window and you will see this:
C:ziphone.exe"
5. type -j -a
and it need to look like this:
C:ziphone.exe" -j -a
6. hit enter and follow directions! Directions looking like this:
ZiPhone v1.0 by Zibri. http://zibree.blogspot.com
Source code available at: http://www.iphone-elite.org
Loading zibri.dat.
Searching for iPhone...
Please power off the iPhone, then hold the home button
and connect to dock to enter recovery mode.
Working...
Please wait 45".
Done!
( To put your iPhone in recovery mode, hold down sleep/wake + Home Button until you see the iTunes logo on your iPhone)
7. Do the same thing with dragging ziphone.exe to cmd and write -u
This looks like this:
C:ziphone.exe" -u
ZiPhone v1.0 by Zibri. http://zibree.blogspot.com
Source code available at: http://www.iphone-elite.org
Loading zibri.dat.
Searching for iPhone...
Working...
Please wait 2'30".
Done!
1. Put iPhone in Dock
2. Copy all files under C:
3. Start/Run --> write cmd --> Hit Enter
4. Drag ziphone.exe into the cmd window and you will see this:
C:ziphone.exe"
5. type -j -a
and it need to look like this:
C:ziphone.exe" -j -a
6. hit enter and follow directions! Directions looking like this:
ZiPhone v1.0 by Zibri. http://zibree.blogspot.com
Source code available at: http://www.iphone-elite.org
Loading zibri.dat.
Searching for iPhone...
Please power off the iPhone, then hold the home button
and connect to dock to enter recovery mode.
Working...
Please wait 45".
Done!
( To put your iPhone in recovery mode, hold down sleep/wake + Home Button until you see the iTunes logo on your iPhone)
7. Do the same thing with dragging ziphone.exe to cmd and write -u
This looks like this:
C:ziphone.exe" -u
ZiPhone v1.0 by Zibri. http://zibree.blogspot.com
Source code available at: http://www.iphone-elite.org
Loading zibri.dat.
Searching for iPhone...
Working...
Please wait 2'30".
Done!
Mad props to Zibri and the elite dev team for their incredible work on this!
http://zibree.blogspot.com/
******cash edit******
This tool also can repair a phone with a "dead" baseband. To quote Zibri's blog
To REPAIR a *DEAD* baseband, do THIS:
Put the iphone in recovery mode (NOT DFU..normal recovery mode)
Then run: ziphone -u
And you will have back IMEI and WIFI.
This procedure already worked on 3 phones.
Put the iphone in recovery mode (NOT DFU..normal recovery mode)
Then run: ziphone -u
And you will have back IMEI and WIFI.
This procedure already worked on 3 phones.