When they gave me a task to make a web2.0 skin, I was absolutely sure: web2.0 has nothing to do with design. All 2.0 sites are 2.0 because of their functionality, not because of their appearance. It’s as simple as that. No skin on earth can single-handedly turn your application into web2.0 if it’s not 2.0 already.
So what is web 2.0?
These are user oriented applications providing services instead of selling product. Usually the service is free (gmail), or low-cost (flickr paid accounts), rarely requires installation and it is updated and maintained on a daily basis ...