OpenPisteMap is now doing near-realtime map updates.

It pulls the latest changes from OpenStreetMap's database every minute and works out which map tiles are out of date. Zoom levels 14-17 are updated immediately, and lower zoom levels updated progressively less frequently.

How far the updates lag behind is dependent on how loaded the server is - expect anything from around 5 minutes up to a few hours, depending on the time of day.