Partition - Sand Box & USB

[Krogenguy]

Can I do the following?
1) Make a complete copy (bootable) of my internal HD to my external USB hard drive
2) Partition my internal HD for a sand box
3) Restart using my OSX startup disk
4) Copy my external HD to my internal HD
5) Create a bootable OS in the sand box
6) Designate the sand box as the startup disk.

Or is there a way to create a sand box partition on the startup HD without going through all of these steps? I like the sand box idea - just not sure how to get there using my USB drive on a powerPC. Since I have two MACs I think I'm going to spend a bunch of time moving & copying my internal HDs.