Tools to pre-download iOS updates Is there a tool for OSX or Windows that will automatically download all the current iOS ipsw files?

I work at a school and when someone has a problem with an iPad and we need to restore it, we have to wait for iTunes or Apple Configurator to download the latest update.
It would be really handy if we could automatically pre download the IPSW files so that they were ready to go as soon as they were needed.
Any ideas?
You can always download the files from ipswdownloader.com.I agree it looks shady but I use it a lot for my development devices and i never have any problems with it.You can also find the ipsw files on your computer as described in this article, you might want to copy the files to another folder though because itunes will remove them automatically.