So, quite a hardcore time in Vegas. If you ever get the chance to get table service in the Mirage's Jet nightclub or the Bellagio's Bank nightclub then you should snap it right up - might cost you though ;o) Anyhow, something that I thought was worthwhile from Defcon 17 was a little tool called FOCA. The name is itself jokes but it is quite interesting.
You probably know all about MS Office/Open Office, etc. documents leaving meta data all over the place - previous authors, dates, changes, etc. Just go have a peek under File --> Options/Summary or Properties and it'll show you. It's old school stuff. Anyway, what I didn't realise was how much information PDF files leaked - internal usernames, hostnames, directories, etc.
What the crazy (...proper crazy) guys at Informatica64 have done is create a pretty neat Win32 application that pulls all of these infoz out and allows you to sort them in a meaningful way. You can even extract badboy usernames and load them straight into Hydra for example. Makes for a nice little information gathering/discovery tool for black box penetration tests.
Anyhow I won't bang on about it too much, you get the picture. PaulDotCom has a nice write up with plenty of screenshots.
PS. Here is the Wikipedia link for all about Metadata if you were like wtf.