Drush Lock: Freeze the version of a Module during 'drush up'

Every so often I will find myself needing to update lots of Drupal modules but not one in particular. Perhaps I have patched the module, or perhaps there is a new version of the theme that I know will break my site layout.
Drush can save you from this dilemma, as of version 4.x - yes, it's true!
Just use:
drush up --lock=omega
Assuming Omega is the project that needs to keep the same version number. Omega will not be updated until you reverse the lock.
drush up --unlock=omega
You can also just:
drush up omega
If you want to.