For those wondering, the easiest way to view your changes to the map quickly is to go to http://www.informationfreeway.org/. Press the plus in the upper-right corner and choose "tiles@home (direct)", 2nd entry. now you can zoom to level 12 and control-click any tile and it will get updated.

You can see if your tile has been rendered here: http://dev.openstreetmap.org/~ojw/Log/Requests/Recent/

You may then need to empty the browser cache to re-download the tile.