Ever wondered whether an instance of SQL is hosted on a virtual or physical server? This query will tell you:
SELECT CASE virtual_machine_type WHEN 1 THEN 'VIRTUAL' ELSE 'PHYSICAL' END as [ServerType] from sys.dm_os_sys_info
You can also determine whether your server is clustered or not via T-SQL:
SELECT CASE SERVERPROPERTY ('IsClustered') WHEN 1 THEN 'YES' WHEN 0 THEN 'NO' END as [CLUSTERED]
These are just a few of the queries I run when I am handed over a server that I have not been responsible for. You can see more of these queries in this post.