In PowerShell v.2, it is very easy to create and maintain your very own event logs to track errors in your scripts or other automation solutions. It's a three-step-journey:
First, create your own event log using New-Eventlog. Note that this requires Admin privileges so you will only need to do this once:
new-eventlog -logname 'Client Login Scripts' -Source 'Logonscript'
Next, you can start writing events to your event log. For example, all of your log-in scripts could log errors this way because logging does not require special Admin privileges:
write-eventlog -logname 'Client Login Scripts' -Source 'Logonscript' `
-Message 'Something bad happened' -id 111
-Message 'Something bad happened' -id 111
To read all logged events, use Get-WinEvent and specify the source as provider name:
Get-WinEvent -providerName Logonscript