Useful Unix Commands: fc
Slowly becoming my favorite, my Useful Unix Command of the moment is: fc
fc allows you to open the last run command in an editor. By default, it will open with the editor set up in $EDITOR (vim for me).
If you have ever had to type a really long command out, and missed something, or wanted to run it for several more files, fc is very useful as it opens in Vim ($EDITOR) and then, upon closing, will run the command again.
This command works on most Linux systems, Unix systems and on Mac OS X. Give it a try.