Fingerprint scanning is yet more evidence that the iPhone was designed in sunny south California rather than chilly northern Europe.
Resistive touch screen may not allow multi-touch, but at least I can use them when wearing gloves (and no - gloves with a capacitive finger tip don't count).
Just because there are segments of the population who can not take advantage of a feature at all times does not mean the feature is unwarranted or designed without considering this fact.
It allows for 5 stored "fingers", so you could set things up for each thumb, each index finger and your nose. Assuming there aren't any security issues about using a nose -- and that you're not worried about security much anyways -- you should be golden. How unique are nose prints?
Resistive touch screen may not allow multi-touch, but at least I can use them when wearing gloves (and no - gloves with a capacitive finger tip don't count).