Numerous fixes: Twitter widget, iPhone rendering, fixed homepage blog rendering

Hi Lynn, 

Sorry it took me longer than it should've to get around to this--I really wanted to make these fixes before the start of PyCon, so I'm hoping I've squeaked this in just in time.
 
* I've added a tested (and working!) Twitter widget that now pulls in tweets from all PyLadies locations
* I fixed the homepage blog rendering, so that the latest two blog posts are now being pulled in programatically, instead of trying to hide all but the first two posts using CSS
* I also made numerous changes to the CSS media queries section to better support rendering on the iPhone in profile view (320px width)

Thanks Lynn!
--Flora