As widely rumored (yep, Kevin Rose was right!), Apple announced Copy and Paste today for iPhone OS 3.0, with "cut" relegated to apps that support it (?).
It works differently in different apps, this is what we can figure out:
Mail & Notes (and 3rd party?): double tap to begin. Drag small delineator icons to start and end of text string you want to copy.
Safari (and embedded browsers): Tap and hold to begin. Selects blocks of text.
Photos: Tap the action button to begin. Select multiple photos to paste into email. (Unknown if Apple will scale or compress before sending?)
Universally, it appears you can shake the iPhone to undo which while gimmicking, is also all kinds of awesome. You can also select paragraphs by holding your finger down on them, and Copy and Paste WILL pick up HTML including text formatting and links!
[Photo via Apple Insider]