Usability 
This week the popular presentation sharing site SlideShare launched a mobile Webapp. Which is something I'm really excited about. If you're ever clicked a link in Twitter or an email using your mobile browser or iPad and found yourself on Slideshare's old non-mobile friendly Flash based site I think you will welcome the change too.
According to SlidesShare the new mobile site supports the iPhone, iPad and Android devices. The images above show it running on an HTC Magic phone running Android 2.2. Even on that old and underpowered device, SlideShare worked well and switching between slides was almost instantaneous.
With most new HTML5 based mobile efforts, Android and iOS are the only platforms supported. So I was pleasantly surprised to find that SlideShare Mobile also worked well with the Samsung bada, WebOS and Opera Mobile 11.1 browsers and even with Opera Mini 6.1. That's no mean feat as proxy based browsers like Opera Mini support a rather limited subset of JavaScript and HTML5.
There is one downside to using an unsupported browser. If you go to Slideshare.net with anything but an Android or iOS browser you will get the desktop version of the site. If that happens you can use the URL slideshare.net/mobile/ to see the mobile version. Also, most older presentations on SlideShare aren't available in mobile format yet but all new ones should be.