Good examples of MapServer / OpenLayers
We're using the OpenLayers Heatmap layer, mostly because (for us) it handles large data volumes better than the Google Map version (your mileage may vary)
http://www.patrick-wied.at/static/heatmapjs/demo/maps_heatmap_layer/openlayers.php
By large data volumes, I mean location datasets with 100K+ rows
It also works nicely as an ASPX page with dynamic realtime data retrieval from an SQL Server database. I've used a stored procedure to pre-process the data into the array format, grouped by Latitude & Longitude.
For those that need a translation table to convert their UK Postcodes into Latitude & Longitude, here's a good source: http://www.doogal.co.uk/UKPostcodes.php
Maybe have a look at the HeatMapAPI for Google Maps (not sure you'll wow the client with that though).
Another density map: http://maps.glassfish.org/server/ (showing the use of GlassFish around the world).
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
http://haiticrisismap.org/ openlayes + geoxt
would it be possible to create a template map for the client with a bunch of data on it, census, socio, create some simple fake buffers.