I updated an application that was using a messy custom error logging mechanism to use ELMAH and it's already saved me time in tracking down problems while updating the app. The app has a custom errors page that shows a few error details to help the user communicate their problem. It was displaying the old mechanism's error ID so we could cross reference it in the error log database. I needed to replace this with the ELMAH version of the same thing. It turns out to be simple, after I figured out which class to use:
System.Collections.IList errorList = new System.Collections.ArrayList(); Elmah.ErrorLog.GetDefault(this.Context) .GetErrors(0, 1, errorList); if(errorList.Count > 0) { Elmah.ErrorLogEntry entry = errorList[0] as Elmah.ErrorLogEntry; // do what you like with 'entry' }