External drives that can boot up Intel iMac

Question

I have just bought an Intel-based iMac.
My previous computer was an iMac G5 (PowerPC). If I needed to boot up from an external drive, it had to be a Firewire drive.
Does anyone know if the Intel iMac is the same? If something were to happen to that system and I needed to boot up from an external drive, does the external have to be Firewire, or will USB 2.0 work as well?
Incidentally, this Intel iMac has one Firewire 800 port. I read a review (although it could have been from last year) that if you have Firewire 400 peripherals, you won't be able to plug them into the FW 800 port unless you have an adapter. Did I read that right? I would have thought that they're simply backward compatible and work just as a USB 1.1 device would if plugged into a USB 2.0 port (the device would just run at the lower 1.1 speed). So where does one get these adapters (if needed)? Does the Apple Store sell them?

Answer 1

or will USB 2.0 work as well?
Yes.
Did I read that right?
Yes. The ports are physically different.
So where does one get these adapters (if needed)?
Click here for an example of what's needed.
Does the Apple Store sell them?
Yes. Click here.
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