Deja Vu What is it?

If you don't remember buying it... you may have installed it as a part of Toast for example. It comes with that or on it's own. It's a backup tool and can also be used to sync files across volumes.

Try removing this plist and then see if it'll start up for you:
com.propaganda.DejaVuPref.plist

 

It's backup software. If you don't remember it, you probably have the version bundled with Toast.

 

I'm positive I've seen that somewhere before...

 

First, in System Preferences, Ctrl-click on the Déjà Vu icon and remove it. Then, trash /Library/PreferencePanes/DejaVu.prefPane to kill it dead.

You can reinstall it from the Toast help menu (setup assistant) if you later decide you want it.

 

Yes, but this isn't one of them.

It's the Library directory under Macintosh HD (or whatever name you use), not your home directory. The folder really should be there...

Yeah, Spotlight is configured to leave system stuff out of its index.