The latest "cool" project I worked on was an "integration" between SQL Server and ElasticSearch[/url].

The full text engine in SQL Server is just not good enough, so we wanted to use something else, but without losing the real-time update of the full text index when changing data in the tables. We ended up with ElasticSearch because it is very easy to work with (REST and JSON based), and very easy to manage and expand.

The "integration" is based on Service Broker, triggers on the tables that is responsible for sending messages, and a Windows service (written in .NET) that listens for new messages and writing updates to ElasticSearch.