How to integrate OpenLayers and ArcGIS Server?

I am using the OpenLayers JavaScript API within a web application. I am displaying non-base layers hosted on an ArcGIS server. When I load the ArcGIS layers, I load them using OpenLayers.Layer.ArcGIS93Rest and by specifying the export service URL. The layer loads perfectly. However, when the user clicks on a feature, I want to be able to display a popup showing information about the feature that the user clicked on. Can anyone explain the best way to retrieve feature information?

Thanks in advance!