Many people don't know this, but if you don't buy an XBOX 360 with a hard drive there is a simple and cheap(ish) alternative to buying a $50-100 hard drive and installing it. There are many flash drives that you can buy and use on your XBOX for storage. The one I have for my own XBOX has 16-20 (a lot) GB of memory, and it was about $20 on Amazon. There is one problem, though. Certain flash drives, i.e. mine, won't fit into any of the USB ports on the console. This instructable will show you how to solve this problem.
Step 1: Try out the flash drive.
First, see if your drive fits into any of the ports. The problem is that the USB ports are located in an indentation in the back of the console, and the exterior design of the drive might not fit into such a narrow space. If your flash drive fits into the port, then my work here is done. If not, read on.