ReSharper Zen Coding PowerToy
is set of plugins for HTML and CSS hi-speed coding.
You can read about it at http://code.google.com/p/zen-coding/
Also, there is starter tutorial in Smashing Magazine
ReSharper ZenCoding PowerToy is way to use such great tool inside Visual Studio.
After installation (pickup version matches version of your VS) you will find new menu items at ReSharper → Power Toys : "Zen Coding" and "Zen Coding Wrap".
For more effective way to use them just assign shortcuts for actions ReSharper_PowerToys_ZenCoding and ReSharper_PowerToys_ZenCodingWrap at Tools → Options → Environment → Keyboard.