Good examples of MapServer / OpenLayers

I want to convince some clients to use MapServer and OpenLayers. Please can anyone suggest attractive websites to show off the possiblities!

The clients will be impressed by:

• A density map (otherwise known as a heat map, colour-shaded grid coverage, contour plot...).
• The ability for the user to download the underlying data for the density map, restricted to the area being viewed, in some format such as netCDF.
• Standard OpenLayers stuff. Zooming, panning, scale bar, overview map...
• Different base layers. Could be WMS, Google, Bing...
• Searching for a placename, map is panned to display the place.
• Exposing the heatmap data for other people to use in mashups as WMS or WCS

MapServer.org is back up but demo.mapserver.org seems to be down right now :( But from memory their examples didn't have the "wow" factor. The OpenLayers examples demonstrate only one or two features per example - I want something to wow the clients by showing all the capabilities in one example.

PS If you have good examples that use some other open source tools, post them by all means. But just JavaScript please: customer says no rich client.

EDIT Come on StackOverflow, someone must have an example that uses a density map?? I'm even offering a bounty now...

Note this answer is no longer relevant. The open source maps have since been replaced with a commercial alternative by a different company

http://maps.seai.ie/wind/ - mapping onshore and offshore wind speeds and farms in Ireland

http://maps.seai.ie/geothermal/ - mapping geothermal temperatures in Ireland, and borehole data

• uses WMS services (and TileCache) for all the layers, so can be accessed by other client GIS's (well once I've set up metadata etc..)
• has a variety of different base maps to choose from
• built using MapFish / ExtJS
• has drop down gazetteers for County and Townland (an Irish administrative unit)
• all the basic map navigation tools and a simple info tool
• right click on a layer to set transparency
• uses MapServer opensource back-end, plus SQL Server 2008

The systems (and a third more complex Bioenergy Intranet system) got a mention here: http://www.geoconnexion.com/uploads/renewableenergy_intv9i4.pdf