I needed to make a script resolve an hostname (FQDN) to the IP address, my first stop for most of these sorts of scripts is the Microsoft Script repository, where I found a lovely function to do just that!
Check out Get-IPAddress at http://gallery.technet.microsoft.com/scriptcenter/44e9fef7-a04b-40b3-bb05-97659e56e27e
Cheers out to Ben Wilkinson for his great work!