Can I copy the entire scrollback buffer from iTerm2 to the clipboard?
Solution 1:
Oh, right, duh. ⌘ + A to select it all, then ⌘ + C.
Solution 2:
To capture your history of commands (but not their output):
history > ~/Desktop/history.txt
If you want output as well, the shell command script works as well to capture while you type (but it captures key presses too, so watch out) or iTerm will have some option to save a session, like the stock Terminal's ⌘ + S.