Datel have announced an unofficial memory card for the Xbox 360, this memory card is 4gb in size, i think it would be perfect for me. I could have all my saves on the memory card along with any DLC / Arcade games, making it easy to move my content between various Xbox 360 consoles. My 64mb memory card at the moment is full with just a couple of profiles on at (almost 10mb each!)
Maybe Datel have found a way to allow any size Sata hard drive to be used in the Xbox 360 too.. we can hope! I plan to purchase one when its out in the UK!