8GB iPhone? These days that is about as useful as a three legged horse. Seriously, I don't get why people are dying to save $100-200 bucks on the initial "investment" even as they contract to spend $60+ a month x 24 on phone service. Maybe if it was an unlocked pay go phone it would make sense but as a contract phone it confounds me people would want it -- but they will.
Speak for yourself. I'm using 4GB of my 8GB 3GS after a year (75% songs, 10% photos, 15% apps). I know people who are barely using 2GB on their iPhones.