What to Pack, is a very, very good site, lots of experience behind it and lots of sound advice - I have little to add except when it comes to travel ultra compact.  Lists e g  good reasons for traveling light. Also Avoiding theft. 

 

One Bag - Doug Dyment, another very good site. The Art and Science of Traveling Light.  Listed advantages: Security Economy, Mobility and Serenity.

 

Light weight trekking, Ray Jardine. Book: Beyond Backpacking. Creative thinking! Moving this art forward! A very inspiring site, for some body into the related field of Ultra Compact Travel.

 

Packing & Traveling Light Recommendations by Mark Veber.  A nice and extensive travel light site. Many links. List advantages of traveling light - but he doesn't suggest carrying all in the trouser pockets. 

  

Peter Cochrane's Blog:  Published: Tuesday 27 September 2005.

"In my wilder moments I dream of a 'no bag' future where I travel wearing everything including all my technology in a fly fishing style jacket including all my extra clothing neatly hidden inside my top coat. The basis being that the airlines measure and weigh bags but not people. But that is something for the future."
  I think the future is here now.  If not, I think my "Unorthodox way of reducing volume of gear like camera, phone, computers etc." can make the difference.

 

The human Swiss Army Knife, Eric, "carrying permanently about his body more than 1,000 useful objects."  No bag! Sure a colleague! 

 

An-apartments-worth-of-furniture-in-a-box  A bit related - many pieces of furniture goes into a quite small box.

 

Links for what is new

Only one suggestion here.

Wearables, which fits the concept of traveling Ultra Compact as long as they are small:

http://digitalcameras.engadget.com/category/wearables/