Mac command line gold!
Copy a file to the clipboard:
$ cat ~/.zshrc | pbcopy
The contents of my .zshrc are now on the clipboard and I can paste them into any other application (Mail.app, Word, whatever).
Paste the clipboard contents to the shell:
$ pbpaste > foo.txt
Anything that was on the clipboard is now in the file foo.txt.
Just figured out how to get git tab completion working in zsh on a Mac. Turns out that the completion scripts use a bunch of extra git commands such as git-ls-files. These commands need to be in your path for the completion to work. If you installed git using the OS X installer, you need to add this directory to your path: