Temporary vector layers

Is there a way of having temporary vector layers which are not persisted when ArcMap is closed down?.

I usually create layers via the IFeatureWorkspace.CreateFeatureWorkspace interface which creates several files on disk in the background.

I want to be able to create some temporary (shapefile/vector) geometry which only exists during the lifetime of the application and thus avoid having to manage the files which are created in the background.

Many thanks in advance for any help

Steve