These are instructions on how to jailbreak your iPhone with QuickPwn. The instructions have been updated for the latest (2.1) version of the iPhone firmware.
Create a folder on your desktop called Pwnage
Download QuickPwn 1.1 from here and place it in the Pwnage folder. Likewise, download the latest 2.1 firmware from below and place it in the same folder.
2.1.0 (2G): iPhone1,1_2.1_5F136_Restore.ipsw
Double click to mount the QuickPwn [QuickPwn_1.1.dmg] archive. Drag the QuickPwn application icon into the Pwnage folder on your desktop.
Double click to launch QuickPwn from the Pwnage folder.
Click OK to accept the copyright notice.
Connect your iPhone to the computer when asked then click the OK button.
QuickPwn will now automatically detect the device connected!
QuickPwn will now automatically search for the latest firmware for this device
You will be asked if you would like to replace the original boot and recovery logos on your iPhone. Select Yes or No to continue.
QuickPwn will now begin building your custom IPSW.
You will be asked to enter your administrator username and password. Do this, then click OK to continue.
QuickPwn will now help you put your iPhone into DFU mode. First, turn off the device.
Next, you will be asked to hold both the Home and Power buttons for 10 seconds.
Finally, you will release the power button and continue holding down the Home button for another 10 seconds.
QuickPwn will now automatically begin sending information to your iPhone.
You will now be notified that QuickPwn is modifying your iPhone. The process will take some time and will cause the iPhone to reboot. Don't do anything until the process has completed!
Once your iPhone has rebooted it will be jailbroken and have both Cydia and Installer on the Springboard!