There are several ways:
Write-HostWrite-Host: Write directly to the console, not included in function/cmdlet output. Allows foreground and background colour to be set.
Write-DebugWrite-Debug: Write directly to the console, if $DebugPreference$DebugPreference set to Continue or Stop.
Write-VerboseWrite-Verbose: Write directly to the console, if $VerbosePreference$VerbosePreference set to Continue or Stop.
The latter is intended for extra optional information, Write-Debug for debugging (so would seem to fit in this case).
Additional: In PSH2 (at least) scripts using cmdlet binding will automatically get the -Verbose and -Debug switch parameters, locally enabling Write-Verbose and Write-Debug (i.e. overriding the preference variables) as compiled cmdlets and providers do.