The Snow Leopard Services menu tells me it's "Building..." but it's been over an hour and the status is still the same. How long is this process supposed to be?
You can manually rebuild the LaunchServices database by entering the following in the Terminal:
In Snow Leopard (thanks to Lawrence Velázquez for pointing this out):
/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Support/lsregister -kill -r -domain local -domain system -domain user
In older versions of the Mac OS X:
/System/Library/Frameworks/ApplicationServices.framework/Frameworks/LaunchServices.framework/Support/lsregister -kill -r -domain local -domain system -domain user
Or read more online where I found the tip: http://www.macosxhints.com/article.php?story=20031215144430486
I went to the trouble of adding this as an alias in my .bashrc file so I could rebuild at whim.
Try logging in to your Administrator account. After this, let it build. For my Finder it did not take more than 2 seconds. When you get a list, it will also be available to all your 'Standard' user accounts.
Cheers :) BBX