The Dev Team posted a message yesterday suggesting that iPhone 3GS owners should prepare their device for jailbreak.
Remember we warned you to stay away from any updates to 3.1 if you want to be able to jailbreak or unlock your 3GS.
Well this is an additional message to all you 3GS owners that would like to jailbreak your device sometime soon, but this advice comes with a warning! A warning that if you accidentally upgrade to 3.1, you will not be able to use Ultransn0w, so please re-read and double check this warning at the bottom of this post before proceeding.
During the restore process iTunes nicely keeps these oh-so-top-secret-files in a lovely accessible place for us to copy out and backup, that place? /tmp on Mac OS X or %TEMP% on Windows. Thanks Apple — handy!
The downside to this approach is that you actually need to go through the restore process to get these signed files, which has risks if you are anywhere near 3.1 or 3.1 beta
Jump the break for instructions on how to get the iBEC and iBSS of your iPhone 3GS.