Boot Windows 7 off of external drive?

[Imuny]

I would like to know if it is possible to boot and run Windows 7 off of an external hard drive. I have looked around a little, and it seems that I need to format a hard drive to make it able to boot right.

Is this right? And how should I go about formatting it?

Also, should I use bootcamp to boot it off of the external, if it is even possible?
If not, what should I use?

I am looking to be able to use both Windows and Mac (not at the same time), and I thought this would be a way to accomplish that.

 

[pdjudd]

Should work just fine, Windows installs to different drives and has dual booting. I would use Bootcamp as well.

 

[Imuny]

How would I go about doing this? Is there any kind of tutorial somewhere?