Bank of habbo.

You can stack bars and stuff, without z shelfs.
Just put it ontop and it will stack like so;
http://img454.imageshack.us/img454/8702/stacksoa4.png

This is my room btw, so I should know.

OMgZZZzzZZ WD

Old pls. Posted numerous times around the forum

not so 'amazing'

already made a tower