Here's an easy way to download your IPSW files and save them on your computer. It's a simple little application called ipswDownloader.
Anyone who jailbreaks their iDevices know about downloading the most recent firmware for their device and either installing it or having their jailbreak software create custom firmware out of it. Well, now it seems that someone has made it even easier to jailbreak with ipswDownloader. The software lets you choose the firmware and device and makes it easy for the user to obtain the firmware they need and store it where they want it.
The software even tells you if the firmware can be unlocked and jailbroken and what app you will need. It's available for both Windows and Mac operating systems.
Windows users will want to hit this download link: Here
Mac OS X users will want to go over to this one: Here
Take a look, it's actually useful even if you don't jailbreak your devices. Of course the most interested probably will be the jailbreakers.
Just to give credit to the developer as well, you can see their site here: iBrain. It's not in English, but hey, at least the developers will feel some of the love, right?