For those of you with an iPhone 3G, early iPhone 3GS, or early iPod Touch 2nd generation, you can now update to iOS 4 and still jailbreak your mobile. Why jailbreak? For one, it will enable wallpaper and multitasking on these devices, which normally is disabled. It also gives you the possibility of unlocking your phone for use with another carrier (but not Verizon or Sprint, due to incompatibilities in phone hardware). Jailbreaking also lets you run software not available in the app store (e.g. Veency, a VNC server which lets you display and control iPhone on another computer, which is great for presentations, or MAME, a vintage arcade game emulator).
Keep in mind that jailbreaking and/or unlocking your mobile phone is completely disapproved of and not in any way supported by Apple, is a violation of your end user license agreement, and is likely to void your warranty. It is also not supported by IvanExpert, Inc and is not a service we will perform for clients.