I totally agree with Ryan and David. I love the following from David (whether his or a quote in of itself):
the genius of AND vs the tyranny of OR
I also think that it is essential to be able to both as a professional. Not necessarily an expert, as already stated, but be comfortable to use either as and when needed even if it requires the support of ones own favourite search engine.
Gaz
-- Stop your grinnin' and drop your linen...they're everywhere!!!