I know I’m extremely late to the party, but I am finally using FastScripts.
Until now, most of the scripts I use are either shell scripts that I activate from inside Terminal, or scripts that I use inside an application that supports them, like BBEdit or BibDesk.
I had tried before to find a way to run scripts from arbitrary applications, but I was never happy with what I found.
Then I found FastScripts, which of course has been around forever. It does everything I want it to. My favorite part is the ability to create application specific scripts and keyboard shortcuts, which are only shown or run when a certain application is running. That way the menu (and more importantly, the keyboard shortcut space) isn’t cluttered with irrelevant scripts.
While I’m on the subject of clutter, I recommend removing system scripts from the FastScripts menu.
Here are some scripts I collected to get my FastScripts library started.