I've found a compilation of companies and their brands' activities on the Internet: minisites, applications and widgets, social networks, videos and corporate blogs:

http://www.globalsocialmedianetwork.com/?page_id=201

http://www.beingpeterkim.com/2008/09/ive-been-thinki.html

To capitalize on popular TV ad Barclaycard  created interactive experience accessible via iPhone game.

Barclaycard Waterslide

Uniqlo is a company that's not afraid to test unorthodox interactive ideas. One is a clock widget embeddable into a webpage. It's simple but aesthetically pleasing application with Japanese girls dancing. The widget was installed to around 250 000 unique pages and was viewed at least 100 million times.