Seeing as Sony are releasing so many different models to try and find the level most consumers are interested in, they should open an online 'create your own PS3 console' store.
Do you want BR included: yes / no
Backward compatible: yes / no
Size of HD: 20 / 40 / 60 / 120
No of USB ports: 1 / 2 / 4
Memory card reader: yes / no
etc etc