Hey,
many people here seem to be interested in searching (academic) publications, see e.g. jstor, pubmed. I have written a simple workflow that searches your local BibDesk library based on Spotlight. This makes finding your PDFs much easier
Download here: BibDesk_Search.alfredworkflow or via alfpt.
Bye
Sebastian
Update 2013-03-25: Recent Version is 2.1 (see thread below)