How do I transfer my stuff from Harddrive to Harddrive

I have a Premium Edition Xbox 360 and I'm considering buying an Elite, but I want to have all the stuff on my 20GB harddrive that came with my Premium 360 on to my harddrive that will come with the 360 Elite. How do I transfer my account, downloaded content, game saves, etc... from harddrive to harddrive, so I can get rid or my old 20 GB hardrive and just use my new120GB harddrive. I want to try avoiding using a computer to do this...

Thanks in adv.

dam thanks... but i just found out my bro has a memory card he can let me borrow, can i transfer my stuff one part at a time through a memory card on to the new harddrive?