Darrin Bishop has useful and informational post on 5 different PowerShell Functions/Filters for SharePoint. quick, click here -
The image from his site is worth the trip alone and then the filters map to the relationship nicely.
These functions can reveal a multitude of information about your implementation and are extremely helpful in teaching about PowerShell, SharePoint and Objects!
#Return an object that is the local SharePoint Farm
$webServices = new-object Microsoft.SharePoint.Administration.SPWebServiceCollection($_)
I highly recommend that you take a visit to Darrin’s blog Five Simple But Powerful PowerShell Functions/Filters for SharePoint for a very easy to follow description of how useful this can be.
Clink! as in a good one to Darrin Bishop and PowerShell. Hey, don’t forget SharePoint!