External Booting

I've been playing with Imaging utilities for Mac. Specifically for OSX 10.5.x.
We have a OSX Server at the Office where I work. Its just a Mac Mini loaded with OSX Server, which at the time is all unplugged sitting in a pile on the floor. Just before it got moved out of the "lab" and into the "conference room" which is now our Lab because we're hiring another person to help us out.

Anyways - long story short.
I used Carbon Copy to image the complete Server via Firewire Targeted Mode (I put the Mini in Targeted Mode) and used a Firewire Cable to my MacBook, which I use a USB to SATA Adapter to which I copied the image to a 2.5" 250gig Laptop SATA Drive. Could have as well been my iPod... I just had the 250gig laying around, why not use it? My iPod is only 4gigs anyways.

I brought the image home, hooked the USB to SATA adapter up to the MacBook, booted holding Option (gives you boot menu) and it will automatically find the USB Adapter and allow you to boot from the external drive just as if it was your internal hard drive.
If you image another persons machine, you will need to know their passwords in order to perform anything. You can reset them if you don't know how but all in all - this is a very easy way to replicate your drive as a backup drive and boot from it - from any mac.

The simple thing would be have an external usb hard drive, image your drive to it (using another computer to pull it from your drive and to the external) then you can take your data/programs/preferences/everything with you anywhere you go...