I've recently completed a chapter for Paul Nielsen's SQL Server 2008 Bible on Scripting with PowerShell. While writing the chapter I created a short script to do a quick inventory of SQL Server information.
Right after I wrote the chapter I was on a consulting assignment where I needed a much more complete inventory of servers, so I expanded the script. I felt it would be useful to others, so I wrote an article and it's now available.
Let PowerShell do an Inventory of your Servers