When I say hidden I mean that this post is really for non USA users of Gmail Google Mail as you already see the features.
I was printing some directions for a trip from my girlfriends account when I noticed the Gmail UI looked a little different to mine. The main big difference was the news feed (Web Clips) headlines at the top of the inbox along with the Chat menu added to the right. I figured she new something about the settings i didn't so i went digging into my settings and found nothing. I went back to her account and looked at her settings, DAMN, I found even more new menues including automatic vacation response
So how has she enabled all this? Simple, and you only have to make one sacrific (and don't worry its nothing like your first born, or similar, your Xbox 360). You just need to go into your settings and change the language to English(US). Obviously this means that colour will be spelt color (which i do now from writing tooooo many stylesheets), and you'll start seeing Z's popping up where you expect S's when you do a spell check. But thats it as far as i can tell.
You can check out the new feature list (for the US) at http://mail.google.com/mail/help/about_whatsnew.html