I know it’s not the time of year when one generally thinks about going to the beach (at least in the UK!) but this web site is a very useful tool for checking on water quality (and air quality) all over Europe. It is a very cool and stylish demonstration of what can be done with Windows Azure, SQL Azure, Bing Maps and Silverlight. You can even get water and air quality reports sent to your mobile phone!
Enjoy the swim!