Another neat use case for Hazel in the context of OmniFocus and any application launcher that leverages the Spotlight search index.

While you can actually search your OmniFocus projects nicely through Spotlight they show up a bit cryptic, if at all, in application launchers like Alfred or Launchbar as this post on the Noodlesoft forums explains.

A simple Hazel rule will fix this and you can search and open your OmniFocus projects nicely from your favourite launcher.