Here are some new features in iOS 4.2 for iPhone that we came across:

Assign text message tone to individual contacts:

Much more after the break:

Enhanced sound preferences:

FaceTime shortcut from Messages app:

New Voice Memos icon:

New App installing/deleting and Mail account editing restrictions:

Liking and Disliking YouTube videos:

Find on page in Safari:

Alerts get silvery shadows: