If you don’t have enough available memory, you can either clear some space by deleting unused saved content or enter your information below to see if you’re eligible for the Memory Upgrade Program.
Apparently you have to see if you qualify, I don't know I don't own a 360.
Since the New Xbox Experience requires 128MB of free space, Microsoft is offering a storage solution for those who may lack the proper storage with either (a) a free 512MB memory unit or (b) a 20GB hard drive for $19.99