Shay Levy’s written a PowerShell function called Get-Sysinternals.ps1. This script looks at the versions of Sysinternals tools on your system (by default in a folder c:\sysint) and downloads any updated versions.
http://blogs.microsoft.co.il/blogs/scriptfanatic/archive/2008/09/06/keep-in-sync-with-sysinternals-tools.aspx