How to change the font on the iPhone 4?

How do you change the font on the iPhone 4?

There are three fonts to choose from in the Notes application. To change go to Settings, scroll down to Notes and your choices are: Noteworthy, Helvetica and Marker Felt. You can also change the font size in Mail, Contacts, Calendars to Small, Medium, Large, Extra Large and Giant. Go to Settings, scroll just a little to Mail, Contacts, Calendars, scroll again to Minimum Font Size and choose the size with a check mark. You can also change the font size in the iBooks app.