Selecting which data to show when browsing OSM online?

Is there any online OSM browser which enables you to select what/which data/layers you want to view? Basically in the same way that Google Earth does when you can select wether or not you want ‘roads’, ‘borders’ etc to be displayed. Preferably done by tags rather than (eg) ‘roads’. I dont know if im just being really stupid with this question, but i cant seem to find something that does this anywhere, and it seems like such an obvious function to have. I am aware that ITO Mapper can do this a bit, but I was hoping for something more advanced. At least something that will allow one to toggle multiple layers, rather than just the one that ITO allows.

Cheers

maybe not exactly what you mean?

http://wiki.openstreetmap.org/wiki/MapJumper