It's so unusual to say..

I rarely use Spotlight. It's slower than Quicksilver.

However, I still want to continue discussing about this matter. Maybe this article will be buried or be criticized by most of people. It doesn't change the fact that spotlight is useless for me. I hate spotlight. I love Quicksilver

Spotlight controller is located..

inside /System/Library/CoreServices in the form of Search.bundle. You can easily go to that folder if you use path finder. Path finder can be activated using keystroke G.

Spotlight will not be displayed in menu bar..

if you remove the Search.bundle from this directory. In order to remove this Search.bundle, you will have to insert your login password as an administrator. I recommend you store the copy of Search.bundle somewhere else in case you regret removing your spotlight. After you've done removing the file, restart your Mac OS X. Then you will not see spotlight in your menu bar.

In this situation..

Spc will not invoke the spotlight. Unviersal access to spotlight has been disabled. However, you still can use spotlight inside Finder Window.

If you want to bring back spotlight..

you can move Search.bundle back to directory /System/Library/CoreServices. If the dialog box appears, you have to choose Authenticate and insert correctly your login password. After that, you have to change the owner and group of Search.bundle to System and Wheel. This can be done under Get Info pane of Search.bundle. To display the pane, you can highlight the file and press I.