I read some days ago that it is possible to organize the PS3 that it can boot between different firmwares in about 3 minutes, although it only works with 3.41 - 3.55 firmware.

You only have to put the folder \updater to your hdd00 folder, and in that one put as many folders as you will have firmwares and name them 01, 02, 03... After that you go to update, and chose to update from stick, and it shows you the different FWs you have on your HDD.

I will probably need to do this, as I will get the Cobra USB stick, and as far as I read, it needs an own CFW from Cobra. So being able to switch FW in 3 minutes would be quite interesting, otherwise you will have to copy firmwares via recovery mode all the time, which takes 30 minutes, and is more "dangerous" to do all the time.

The REAL booting different firmwares, like newer ones than 3.55, only works with the PS3 E3 flasher so far, but who knows?