Have a look at some of the technology used on EZlocal:
All of our sites are built with Microsoft's ASP.NET 3.5 and in places use the ASP.NET AJAX framework. We are phasing out are usage of the .NET AJAX framework, and moving towards jQuery delivered by Google.
We live 100% off of Windows servers. We use Microsoft SQL Server 2000, 2005 and 2008 as well as MySQL for our database solutions. Some of our full text search is powered by Sphinx. Our blog is powered by BlogEngine.NET and some of our mail services are powered by AuthSMTP.
We use various content providers. Some business data provided by Localeze. Local weather, events and geo-encoding services are obtained via Yahoo! and local news is provided by Topix. Job listings are provided by work4abc.com and Indeed. Maps are generated via the Google Maps API. Some photos are results of the Yahoo/Flickr API.