How to dual-boot your iPhone April 1st, 2008
byMulti-booting means having the capacity for a computer to boot up different operating environments at any given time. This has been made popular, imho, when users were tinkering with Linux and Windows at the same time. Some folks prefer to have Windows as a fallback OS should Linux fail them.
Dual-booting on a mobile phone is something unique and I must say that this is my first time to have seen it. This seems to be the way hackers are testing new Apple firmware unlocking before releasing the final version for public consumption. Sounds like it is of no use to consumers, huh? Well, with the iPhone SDK now out and with a different firmware as what is currently available on iTunes, developers may want to actually test this firmware alongside their existing firmware on a real device. So how do we do it? Here's is a tutorial on how you can do it. Warning, though, it may brick your iPhone so please do not blame us when you end up with an iBrick. 
I wish I have a spare iPhone to play with but I don't so I leave this to you as an experiment. Will you be trying it out?