Here to take your prep work to bold new extremes is Gist, a website that melds your inbox to the web...all in the name of strengthening and organizing your research. (By which we mean cyber-stalking.)
Say you're keeping her email handy in your inbox, since it has her address for tonight, just above that email from your agent with some dirt on that producer you're meeting next week. If you've already gotten the Gist, the service will use that info you have to find a whole lot more that you don't—it'll crawl blogs, LinkedIn, Twitter and other corners of the web you don't have time for.
The result: a deep all-in-one-place portfolio of her likes (the band she saw last night, according to Twitter) and dislikes (the actor she went with, according to Perez Hilton). Below that, in your bushel on the producer, you might find a just-posted article by Nikki Finke that tells you the producer is lying to you. (Shocking, we know.)
The site's currently in beta, so you'll want to email them for an invite now—or else you'll be stuck with your truly archaic modes of gathering information on a person.
You know, like talking to them.