In the browser, you have the global scope in the window object o it's pretty easy to define a construct for namespaces.

I thought about the namespaces thing and it sounds like a better idea than encapsulating stuff into anonymous functions so I made a little boilerplate that implement basic OOP features:

http://jsfiddle.net/L4Tcw/21/

Only thing that I think smells a bit is having to keep a reference to 'this' of the main object.