Apple seems to have equipped iTunes 8 to detect and prevent the Pwnage exploit, iTunes 8 will now flash the error below if you try to load an Pwned IPSW file with an unPwned device preventing the exploit to suceed.
The famous iPhone Dev Team have released another iPhone Jailbreaking utility - "QuickPwn", as the name suggest the Windows only batch files let users jailbreak iPhone more quickly and easily without requiring a full restore, the software is labeled as pre-release developmental snapshot so better handle with care.
Apple has made iPhone very restricted in terms of customization, but there are ways to bypass these restrictions and install custom themes, "iPhone Hack Toolkit" is a free iPhone jail-breaking software.