From Library Garden:
Thank you for coming–we love to share our space and are happy to have you here. As in many libraries (and I suspect in yours), we have a policy here that states: No Food or Drink in the Library. We hate to tell our patrons no, but have no choice—this is a sensible policy as food and drink stain furniture and carpets and destroys library materials. In this age of the ubiquitous Starbucks cup, coffee cop is one of the worst parts of our jobs.
http://librarygarden.blogspot.com/2009/02/open-letter-to-visiting-professionals.html
I just left a comment. Take a read and see what you think.