We recently launched sketchfab.com, a free service to publish interactive 3D models online without plugin, using WebGL and HTML5.
We are working on exporters to be able to upload directly from within 3D softwares to the web via Sketchfab API. So far, we have exporters for blender, SketchUp and 3dsMax: http://blog.sketchfab.com/tag/exporters
We are looking for someone to help us build an exporter for Zbrush. It would export as obj, put all ressources (texture, mtl...) in a zip file then upload it on our server.