Jailbreak tools such as redsn0w require users to download firmware files from Apple in order to pwn the device. Hunting around the web for these files can be a pain (and potentially unsafe), so developer Vitaly Parovishnik has created a simple Mac application called ipswDownloader to do the dirty work for you.
The app has two drop-down menus, one for gadget model and one for firmware version. In addition to downloading the .ipsw file, the app will also show you the latest jailbreak and unlock status for the device/firmware combo in question, along with the file size and additional info. ipswDownloader will make an excellent addition to any jailbreaker’s toolbox, and is perfect for assisting your non tech-savvy friends.